Calcium Supplementation During Pregnancy for Preventing Hypertensive Disorders Is not Associated with Changes in Platelet Count, Urate, and Urinary Protein: a Randomized Control Trial Maternal calcium supplementation and fetal bone mineralization. Calcium supplements and bone resorption in pregnancy: a randomized crossover trial. Effects of calcium supplementation on fetal growth in mothers with deficient calcium intake: a randomised controlled trial. Effect of calcium plus vitamin D supplementation during pregnancy in Brazilian adolescent mothers: a randomized, placebo-controlled trial. Randomized, placebo-controlled, calcium supplementation study in pregnant Gambian women: effects on breast-milk calcium concentrations and infant birth weight, growth, and bone mineral accretion in the first year of life. Calcium requirements of lactating Gambian mothers: effects of a calcium supplement on breast-milk calcium concentration, maternal bone mineral content, and urinary calcium excretion. Effect of Calcium Supplementation on Blood Lead Levels in Pregnancy: A Randomized Placebo-Controlled Trial Effect of maternal calcium supplementation on offspring blood pressure in 5- to 10-y-old rural Gambian children123 Gestational calcium supplementation and blood pressure in the offspring. Maternal calcium supplementation during pregnancy and dental caries of children at 12 years of age: follow‐up of a randomized controlled trial Calcium supplementation in pre-eclampsia. The effect of calcium supplementation on bone density during lactation and after weaning. Calcium supplementation for the prevention of pre-eclampsia. Calcium supplementation reduces blood pressure during pregnancy: results of a randomized controlled clinical trial. Randomized, placebo-controlled, calcium supplementation trial in pregnant Gambian women accustomed to a low calcium intake: effects on maternal blood pressure and infant growth1234 Effect of calcium supplementation in pregnancy on maternal bone outcomes in women with a low calcium intake123 Maternal plasma 25-hydroxyvitamin D concentration and birthweight, growth and bone mineral accretion of Gambian infants Effects of Calcium Supplementation on Body Weight and Adiposity in Overweight and Obese Adults Calcium Supplementation and the Risk of Preeclampsia in Ecuadorian Pregnant Teenagers Calcium supplementation during pregnancy may reduce preterm delivery in high-risk populations. Prevention of Pregnancy‐Induced Hypertension by Calcium Supplementation in Angiotensin II‐Sensitive Patients Effects of Dietary Calcium Intervention on Adolescent Mothers and Newborns: A Randomized Controlled Trial World Health Organization randomized trial of calcium supplementation among low calcium intake pregnant women. Calcium supplementation and prevention of pregnancy induced hypertension. Preliminary evidence of the effect of calcium supplementation on blood pressure in normal pregnant women. Effect of milk and calcium supplementation on bone density and bone turnover in pregnant Chinese women: a randomized controlled trail Effects of calcium supplementation on uteroplacental and fetoplacental blood flow in low-calcium-intake mothers: a randomized controlled trial. Trial of Calcium for Preeclampsia Prevention (CPEP): rationale, design, and methods. [Effects of different levels of calcium intake on bone of pregnant women]. Supplementary calcium in prevention of pre-eclampsia. Calcium Supplementation in Mild Preeclampsia Remote From Term: A Randomized Double‐Blind Clinical Trial Calcium supplementation does not alter lipid oxidation or lipolysis in overweight/obese women. Calcium and low-dose aspirin prophylaxis in women at high risk of pregnancy-induced hypertension. Calcium and iron absorption: mechanism of action and nutritional importance. Impact of calcium supplementation in the preceding pregnancy on the human milk calcium concentration of Gambian women. Long term effect of calcium supplementation during pregnancy on the blood pressure of offspring: follow up of a randomised controlled trial Calcium supplementation reduces the risk of pregnancy‐induced hypertension in an Andes population Nutritional supplementation during pregnancy and offspring cardiovascular disease risk in The Gambia. Biochemical changes associated with blood pressure reduction induced by calcium supplementation during pregnancy. [Calcium for the treatment of leg cramps during pregnancy]. A Randomized Controlled Trial of the Effect of Third‐Trimester Calcium Supplementation on Maternal Hemodynamic Function Calcium and magnesium status in pregnant women. A comparison between treatment with calcium and vitamin C in pregnant women with leg cramps.
Objective . To test the hypothesis that calcium supplementation inhibits the underlying pathological processes in women with preeclampsia . Methods . Seven hundred and eight nulliparous women were enrolled in a WHO r and omized double-blind trial , who received 1.5 g of calcium or placebo from 20 weeks of pregnancy or earlier . Platelet count , serum urate , and urinary protein/creatinine ratio were measured at or near 35 gestational weeks . Results . No difference was detected in rates of abnormal platelet count ( relative risk [ RR ] 1.18 ; 95 % confidence interval [ CI ] , 0.63 to 2.18 ) , serum urate level ( 1.0 ; 0.64 to 1.57 ) or urine protein/creatinine ratio ( 1.01 ; 0.76 to 1.34 ) . This was consistent with the main trial finding of no difference in the incidence of ‘ dipstick ’ proteinuria between women receiving calcium and those receiving placebo ( 8312 women ; RR , 1.01 ; 95 % CI , 0.88 to 1.15 ) . Conclusions . An effect of calcium supplementation in the second half of pregnancy on the rate of abnormal laboratory measures associated with preeclampsia was not demonstrated OBJECTIVE To determine the effect of maternal calcium supplementation during pregnancy on fetal bone mineralization . METHODS Healthy mothers with early ultrasound confirmation of date s and singleton pregnancies were enrolled in a double-masked study and r and omized before 22 weeks ' gestation to 2 g/day of elemental calcium or placebo until delivery . Maternal dietary intake at r and omization and at 32 - 33 weeks ' gestation was recorded with 24-hour dietary recalls . Dual-energy x-ray absorptiometry measurements of the whole body and lumbar spine of the neonates were performed before hospital discharge . RESULTS The infants of 256 women ( 128 per group ) had dual-energy x-ray absorptiometry measurements during the first week of life . There were no significant differences between treatment groups in gestational age , birth weight , or length of the infants , or in the total-body or lumbar spine bone mineral content . However , when bone mineral content was analyzed by treatment group within quintiles of maternal dietary calcium intake , total body bone mineral content ( mean + /- st and ard error of the mean ) was significantly greater in infants born to calcium-supplemented mothers ( 64.1+/-3.2 versus 55.7+/-2.7 g in the placebo group ) in the lowest quintile of dietary calcium intake ( less than 600 mg/day ) . The effect of calcium supplementation remained significant after adjustment for maternal age and maternal body mass index and after normalization for skeletal area and body length of the infant . CONCLUSION Maternal calcium supplementation of up to 2 g/day during the second and third trimesters can increase fetal bone mineralization in women with low dietary calcium intake . However , calcium supplementation in pregnant women with adequate dietary calcium intake is unlikely to result in major improvement in fetal bone mineralization BACKGROUND Pregnancy is a time of increased need for calcium . The role of calcium supplements in altering maternal responses to fetal dem and for calcium is not fully understood . This article describes the results of a r and omized , crossover trial of calcium supplementation on bone resorption among pregnant women . DESIGN / SETTING PARTICIPANTS : Thirty-one Mexican women at 25 - 35 weeks gestation participated in the study for 20 days . Each woman received a 1200 mg calcium supplement on 10 consecutive days and a multivitamin without calcium for 10 days . Urine sample s were collected daily . Two pooled specimens from each subject ( representing urine from multivitamin days and from calcium days ) were preserved , and levels of cross-linked , N-telopeptides of type I collagen ( NTX ) , a biomarker of bone resorption , were measured . Dietary calcium intake was assessed using a food-frequency question naire . RESULTS Of the 31 participants , 27 ( 87.1 % ) showed reductions in urinary NTX levels while ingesting calcium supplements . When not ingesting calcium , NTX levels for the 31 subjects had a mean of 96.8 nM BCE/mM creatinine ; this was significantly higher ( p<0.001 ) than the mean urinary NTX levels of 83.2 nM BCE/mM creatinine during ingestion of the calcium supplements . Neither age nor dietary calcium intake was a significant predictor of treatment effect . CONCLUSION A bedtime , 1200-mg calcium supplement during the third trimester of pregnancy reduces maternal bone resorption by an average of 13.6 nM BCE/mM creatinine ( 14 % ) , as reflected by urinary NTX levels . These results suggest that calcium supplements reduce maternal skeletal-bone turnover during the third trimester of pregnancy Calcium supplementation in mothers with low calcium intake has been of interest recently because of its association with optimal fetal growth and improved pre-eclampsia-related outcomes . While the effects of calcium supplementation have demonstrated benefits in prolonging gestation and subsequently improving birthweight , no specific studies have identified the longitudinal effects of supplementation on fetal growth in utero . Data were analysed in the context of the World Health Organization trial of calcium supplementation in calcium-deficient women . Five hundred and ten healthy , primiparous pregnant Argentinean women were r and omised ( at < 20 weeks gestation ) to either placebo  ( n = 230 ) or  calcium supplements ( 1500 mg calcium/day in 3 divided doses ; n = 231 ) . Growth parameters in utero were assessed with serial ultrasound scans . Birthweight , length , head , abdominal and thigh circumferences were recorded at delivery . No differences were found in fetal biometric measurements recorded at 20 , 24 , 28 , 32 and 36 weeks gestation between fetuses of women who were supplemented with calcium and those who were not . Similarly , neonatal characteristics and anthropometric measurements recorded at delivery were comparable in both groups . We conclude that calcium supplementation of 1500 mg calcium/day in pregnant women with low calcium intake does not appear to impact on fetal somatic or skeletal growth BACKGROUND Pregnancy and lactation in adolescents with habitually low calcium intake may adversely affect maternal bone mass . OBJECTIVE We investigated the effect of calcium plus vitamin D supplementation during pregnancy on bone mass during lactation in Brazilian adolescent mothers with low-calcium diets ( ∼600 mg/d ) . DESIGN Pregnant adolescents ( 14 - 19 y ) r and omly received daily calcium ( 600 mg ) plus vitamin D3 ( 200 IU ) ( n = 30 ) or a placebo ( n = 26 ) from 26 wk of pregnancy ( baseline ) until parturition . The bone mineral content ( BMC ) , bone area ( BA ) , and bone mineral density ( BMD ) at the total body , lumbar spine , and hip ( total and femoral neck ) were evaluated by using dual-energy X-ray absorptiometry at 5 and 20 wk postpartum . Serum hormones and 25-hydroxyvitamin D [ 25(OH)D ] were measured . Group comparisons were adjusted for significant covariates . RESULTS The mean serum 25(OH)D concentration was 59 nmol/L at baseline . In comparison with the placebo , 25(OH)D tended to be 14 - 15 nmol/L higher postpartum in the supplemented group ( P = 0.08 ) . Total body and hip BMC and BMD decreased over time ( P ≤ 0.005 ) in both groups with a group × time interaction at the femoral neck ( P < 0.04 ) . Supplemented mothers had higher lumbar spine BA ( 6.7 % ; P = 0.002 ) and lumbar spine BMC ( 7.9 % , P = 0.08 ) than did mothers who consumed the placebo at 5 wk postpartum . At 20 wk postpartum , differences between groups were more evident , with higher lumbar spine BMC ( 13.9 % ) , lumbar spine BA ( 6.2 % ) , and lumbar spine BMD ( 10.6 % ) in the supplemented group ( P ≤ 0.008 ) . CONCLUSIONS Calcium plus vitamin D supplementation during pregnancy of adolescents with low calcium intake  results in higher lumbar spine bone mass and a reduced rate of femoral neck bone loss during lactation . Additional studies are required to determine whether bone effects are temporary or long-lasting . This trial was registered at clinical trials.gov as NCT01732328 BACKGROUND Growth and bone mineral accretion in Gambian infants are poorer than those in Western population s. The calcium intake of Gambian women is low , typically 300 - 400 mg Ca/d , and they have low breast-milk calcium concentrations , which result in low calcium intakes for their breastfed infants . A low maternal calcium supply in pregnancy may limit fetal mineral accretion and breast-milk calcium concentrations and thereby affect infant growth and bone mineral accretion . OBJECTIVE We investigated the effects of calcium supplementation in Gambian women during pregnancy on breast-milk calcium concentrations and infant birth weight , growth , and bone mineral accretion . DESIGN A r and omized , double-blind , placebo-controlled supplementation study was conducted in 125 Gambian women who received 1500 mg Ca/d ( as calcium carbonate ) or placebo from 20 wk of gestation until delivery . Infant birth weight and gestational age were recorded . Breast milk was collected , and infant anthropometric and bone measurements were performed at 2 , 13 , and 52 wk after delivery . Infant bone mineral status was assessed by using single-photon absorptiometry of the radius and whole-body dual-energy X-ray absorptiometry . RESULTS Compliance with the supplement was high . No significant differences were detected between the groups in breast-milk calcium concentration , infant birth weight , or growth or bone mineral status during the first year of life . A slower rate of increase in infant whole-body bone mineral content and bone area was found in the supplement group than in the placebo group ( group x time interaction : P = 0.03 and 0.02 , respectively ) . CONCLUSION Calcium supplementation of pregnant Gambian women had no significant benefit for breast-milk calcium concentrations or infant birth weight , growth , or bone mineral status in the first year of life The calcium requirement for prolonged lactation was investigated in a r and omized supplementation study of Gambian mothers consuming a low-calcium diet ( 7.1 mmol/d , or 283 mg/d ) . Sixty women were studied from 10 d to 78 wk of lactation , receiving calcium or placebo for the first 12 mo . The supplement increased average calcium intake by 17.9 mmol/d ( 714 mg/d ) . Supplementation had no effect on breast-milk calcium concentration or on maternal bone mineral content . Urinary calcium output was higher in supplemented than in unsupplemented mothers by 1.18 mmol/d ( 47 mg/d ) , P < or = 0.005 . Longitudinal changes in urinary calcium output and bone mineral content made a substantial contribution to calcium requirements for lactation . This study suggests that , in women with low calcium intakes , there is no direct benefit from increasing calcium intake during lactation , and that physiological mechanisms operate to furnish calcium for breast-milk production Background Prenatal lead exposure is associated with deficits in fetal growth and neurodevelopment . Calcium supplementation may attenuate fetal exposure by inhibiting mobilization of maternal bone lead and /or intestinal absorption of ingested lead . Objective Our goal was to evaluate the effect of 1,200 mg dietary calcium supplementation on maternal blood lead levels  during pregnancy . Methods In a double-blind , r and omized , placebo-controlled trial conducted from 2001 through 2003 in Mexico City , we r and omly assigned 670 women in their first trimester of pregnancy to ingest calcium ( n = 334 ) or placebo ( n = 336 ) . We followed subjects through pregnancy and evaluated the effect of supplementation on maternal blood lead , using an intent-to-treat analysis by a mixed-effects regression model with r and om intercept , in 557 participants ( 83 % ) who completed follow-up . We then conducted as-treated analyses using similar models stratified by treatment compliance . Results Adjusting for baseline lead level , age , trimester of pregnancy , and dietary energy and calcium intake , calcium was associated with an average 11 % reduction ( 0.4 μg/dL ) in blood lead level relative to placebo ( p = 0.004 ) . This reduction was more evident in the second trimester ( −14 % , p < 0.001 ) than in the third ( −8 % , p = 0.107 ) and was strongest in women who were most compliant ( those who consumed ≥ 75 % calcium pills ; −24 % , p < 0.001 ) , had baseline blood lead > 5 μg/dL ( −17 % , p < 0.01 ) , or reported use of lead-glazed ceramics and high bone lead ( −31 % , p < 0.01 ) . Conclusion Calcium supplementation was associated with modest reductions in blood lead when administered during pregnancy and may constitute an important secondary prevention effort to reduce circulating maternal lead and , consequently , fetal exposure Background : Evidence suggests that increased maternal calcium intake during pregnancy may result in lower offspring blood pressure , prompting calls for more robust data in this field , particularly in setting s of habitually low calcium intake . Objective : The objective was to investigate the effect of maternal calcium supplementation on blood pressure in offspring by recruiting children born after a r and omized , double-blind , placebo-controlled trial of  calcium  supplementation during pregnancy . Design : Children ( n = 389 ) from a rural area of The Gambia ( mean age : 7.4 ± 1.2 y ; range : 5–10 y ) , whose mothers received a calcium supplement ( 1500 mg Ca/d from 20 wk of gestation until delivery )  or placebo , were followed up in West Africa . Blood pressure was assessed under st and ardized conditions with use of the Omron 705IT automated oscillometric device ( Morton Medical Ltd , London , United Kingdom ) , and anthropometric and body composition ( bioelectrical impedance ) measurements were also made . Results : The analysis was restricted to 350 children born at term , which represented 64 % of original trial births . There was no difference in systolic ( adjusted mean difference : −0.04 mm Hg ; 95 % CI : −1.78 , 1.69 mm Hg ) or diastolic ( adjusted mean difference : 0.25 mm Hg ; 95 % CI : −1.27 , 1.77 mm Hg ) blood pressure between children whose mothers had received calcium and those who received placebo . No interaction between childhood body mass index ( in kg/m2 ; mean : 14.0 ) and maternal calcium supplementation was observed in this study . Conclusion : Calcium supplementation in the second half of pregnancy in Gambian women with very low habitual calcium intakes may not result in lower offspring blood pressure at 5–10 y of age BACKGROUND The current study examined the relationship between calcium supplementation  during pregnancy and blood pressure ( BP ) in the mother and offspring at 3 months and at 2 years postpartum . METHODS Nulliparous pregnant women were assigned to either receive 2 g of calcium or placebo daily beginning between weeks 13 to 21 of gestation and continuing until delivery . Blood pressure was measured in children and their mothers at 3 months ( n = 260 ) and ( n = 57 ) at 2 years postpartum . Systolic BP was measured in the infants using a sphygmomanometer with ultrasonic amplification . For the toddlers , three supine BP measurements were taken from the right arm using a Critikon automated sphygmomanometer just after measurement of left ventricular wall thickness . RESULTS Systolic BP in the calcium-supplemented infants was 2.2 mm Hg lower than in the placebo group ( P > .05 ) . At 2 years of age , systolic BP was 4.8 mm Hg lower in the calcium supplemented group ( P < .05 ) , whereas diastolic BP was 3 mm Hg lower ( P > .05 ) . There was no difference in left ventricular mass index between groups , although there was a significant correlation between systolic BP and wall thickness ( P < .05 ) . Maternal BP was positively correlated with circulating 1,25(OH)(2)D3 ( P < .001 ) but did not differ between calcium groups at 3 months postpartum . CONCLUSIONS The data on BP in the children are in agreement with previous studies and argue strongly for additional research into the effects of prenatal calcium supplementation on BP regulation in the offspring Objectives . To evaluate if calcium supplementation during pregnancy could have any influence on primary dentition measured as the reduction of  dental caries of the child . Design . Individual r and omized controlled trial . Setting . One hospital in Rosario , Argentina . Population . R and om sample of 195 12‐year‐old children from a follow‐up study of 614 women who were r and omized during pregnancy to calcium supplementation or placebo .  Methods . An independent research er blinded to the group where the mothers were assigned performed a dental examination of the children . Main outcome measures . Proportion of children with at least one decayed , missing or filled teeth ( DMFT/dmft ) and mean number of decayed , missing or filled surfaces ( DMFS/dmfs ) per children . Results . Ninety‐eight children were assessed in the calcium supplementation group and 97 in the placebo group . 63.3 % of the children whose mother took calcium supplementation had at least one DMFT/dmft compared to 86.6 % in the placebo group ( < 0.001 ) . The children whose mother received the intervention had a 27 % reduction in the risk of developing at least one DMFT/dmft ( RR : 0.73 , CI 95 % : [ 0.62 ; 0.87 ] ) . Conclusions . This study shows a modeling effect of calcium intake during pregnancy on dental caries of the offspring . At around 12 years of age children whose mothers received calcium supplementation when pregnant showed a significant reduction in dental caries OBJECTIVE The objective of this prospect i ve , open , r and omised trial was to determine the role of calcium supplementation in preventing pre-eclampsia . METHODS One hundred uncomplicated normotensive primigravidae were enrolled in the study before 20 weeks of pregnancy . Fifty each were r and omised to receive either two gram elemental calcium daily from 20 weeks of gestation to delivery ( study group ) or no calcium supplementation ( control group ) . Prior to 20 weeks of gestation each underwent a complete clinical and laboratory evaluation . Serum and urine calcium was measured first at 20 weeks of gestation and then at 24 - 28 weeks and at 32 - 36 weeks of pregnancy . RESULTS Patient characteristics at the start of therapy were similar in the two groups .  Blood pressure profile was similar throughout pregnancy in the groups . The incidence of pre-eclampsia was similar ( 18 % in the study group and 16 % in the control group ) , but severe pre-eclampsia was significantly less in the study group . There was no significant difference between the two groups with regards to intra- and postpartum characteristics , perinatal outcome and maternal or fetal side effects . Serum and urinary calcium levels did not differ between the two groups . CONCLUSION While calcium supplementation did not lower the incidence of pre-eclampsia it did reduce its severity BACKGROUND Women may lose bone during lactation because of calcium lost in breast milk . We studied whether calcium supplementation prevents bone loss during lactation or augments bone gain after weaning . METHODS We conducted two r and omized , placebo-controlled trials of calcium supplementation ( 1 g per day ) in postpartum women . In one trial ( the study of lactation ) , 97 lactating and 99 nonlactating women were enrolled a mean ( + /-SD ) of 16+/-2 days post partum . In the second trial ( the study of weaning ) , 95 lactating women who weaned their infants in the 2 months after enrollment and 92 nonlactating women were enrolled 5.6+/-0.8 months post partum . The bone density of the total body , lumbar spine , and forearm was measured at enrollment and after three and six months . RESULTS The bone density of the lumbar spine decreased by 4.2 percent in the lactating women receiving calcium and by 4.9 percent in those receiving placebo and increased by 2.2 and 0.4 percent , respectively , in the nonlactating women ( P<0.001 for the effect of lactation ; P= 0.01 for the effect of calcium ) . After weaning , the bone density of the lumbar spine increased by 5.9 percent in the lactating women receiving calcium and by 4.4 percent in those receiving placebo ; it increased by 2.5 and 1.6 percent , respectively , in the nonlactating women ( P<0.001 for the effects of lactation and calcium ) . There was no effect of either lactation or calcium supplementation on bone density in the forearm , and there was no effect of calcium supplementation on the calcium concentration in breast milk . CONCLUSIONS Calcium supplementation does not prevent bone loss during lactation and only slightly enhances the gain in bone density after weaning OBJECTIVE To study the effect of calcium supplementation during pregnancy on blood pressure and maternal and neonatal outcomes . METHOD A total of 524 healthy primigravidas with a blood pressure less than 140/90 mm Hg were r and omly assigned between the 12th and 25th weeks to receive 2 g of elemental calcium or placebo and were followed-up until delivery . RESULTS The incidence of pre-eclampsia was significantly less in the calcium than in the placebo group ( 4.0 % vs 12.0 % ; odds ratio [ OR ] , 0.31 ; 95 % confidence interval [ CI ] , 0.15 - 0.63 ) ; the mean systolic and diastolic blood pressures at study completion were different in the calcium and placebo group ( P=0.007 and P=0.02 ) . The risk for preterm delivery was less in the calcium ( 7.0 % ) than in the placebo ( 12.7 % ) group ( OR , 0.51 ; 95 % CI , 0.28 - 0.93 ) . The mean baseline calcium intake was 313.83+/-203.25 mg/day ( range , 85.71 - 910.71 mg/day ) , which is lower than the recommended dietary intake of 1000 mg , and the 24-hour urinary calcium excretion was 130.82+/-67.44 mg/dL ( range , 40.5 - 387 mg/dL ) . CONCLUSION Calcium supplementation appears to reduce the occurrence of pre-eclampsia and preterm delivery in primigravidas who have a daily dietary calcium intake less than the recommended dietary allowances Fifty-two healthy pregnant women were enrolled in a double-blind , r and omized , controlled clinical trial . After the 26th week of gestation , the women were given either 1.5 g of elemental calcium per day or a placebo . Subjects in the calcium group , after adjustment for race and initial blood pressure ( BP ) , had a term mean systolic and diastolic BP value of 4 - 5 mmHg lower than those in the placebo group ( P less than .05 ) . The incidence of pregnancy-induced hypertension was 11.1 % in the placebo group and 4.0 % in the calcium group , a nonsignificant difference . Combining these values with previous data , we found a dose-effect relationship between calcium intake and BP reduction during the third trimester of pregnancy . Further research should be directed at underst and ing the mechanism of this effect and trying to demonstrate a reduction in pregnancy-induced hypertension with calcium supplementation in a larger population Background : Dietary calcium intake in rural Gambian women is very low ( ∼350 mg/d ) compared with international recommendations . Studies have suggested that calcium supplementation of women receiving low-calcium diets significantly reduces risk of pregnancy hypertension . Objective : We tested the effects on blood pressure ( BP ) of calcium carbonate supplementation ( 1500 mg Ca/d ) in pregnant , rural Gambian women . Design : The study was a r and omized , double-blind , parallel , placebo-controlled supplementation trial from 20 wk of gestation ( P20 ) until delivery ( calcium : n = 330 ; placebo ; n = 332 ) . BP and anthropometric measures were taken at P20 and then 4 weekly until 36 wk of gestation ( P36 ) , and infant anthropometric measures were taken at 2 , 13 , and 52 wk postdelivery . Results : A total of 525 ( calcium : n = 260 ; placebo : n = 265 ) women had BP measured at P36 and subsequently delivered a healthy term singleton infant . Mean compliance was 97 % , and urinary calcium measures confirmed the group allocation . At P20 , the mean ( ±SD ) systolic blood pressure ( SBP ) was 101.2 ± 9.0 and 102.1 ± 9.3 mm Hg , and diastolic blood pressure ( DBP ) was 54.5 ± 7.3 and 55.8 ± 7.8 mm Hg , in the calcium and placebo groups , respectively . The intention-to-treat analysis that was adjusted for confounders showed no significant effect of calcium supplementation on the change between P20 and P36 ( calcium compared with placebo ; mean ± SEM ) in SBP ( −0.64 ± 0.65 % ; P = 0.3 ) or DBP ( −0.22 ± 1.15 % ; P = 0.8 ) . There was no significant effect of supplementation on BP , pregnancy weight gain , weight postpartum , or infant weight , length , and other measures of growth . However , the comparability of the original r and omly assigned groups may have been compromised by the exclusion of 20.7 % of women from the final analysis . Conclusions : Calcium supplementation did not affect BP in pregnancy . This result may have been because the Gambian women were adapted to a low dietary calcium intake , and /or obesity , high gestational weight gain , high underlying BP , tobacco use , alcohol consumption , and sedentary lifestyles were rare . This trial was registered at the International St and ard R and omized Controlled Trial Register ( www.controlled-trials.com/m rct / ) as IS RCT N96502494 Background : Mobilization of maternal bone mineral partly supplies calcium for fetal and neonatal bone growth and development . Objective : We investigated whether pregnant women with low calcium intakes may have a more extensive skeletal response postpartum that may compromise their short- or long-term bone health . Design : In a subset of participants ( n = 125 ) in a double-blind , r and omized , placebo-controlled trial ( International Trial Registry : IS RCT N96502494 ) in pregnant women in The Gambia , West Africa , with low calcium intakes ( ≈350 mg Ca/d ) , we measured bone mineral status of the whole body , lumbar spine , and hip by using dual-energy X-ray absorptiometry and measured bone mineral status of the forearm by using single-photon absorptiometry at 2 , 13 , and 52 wk lactation . We collected blood and urine from the subjects at 20 wk gestation and at 13 wk postpartum . Participants received calcium carbonate ( 1500 mg Ca/d ) or a matching placebo from 20 wk gestation to parturition ; participants did not consume supplements during lactation . Results : Women who received the calcium supplement in pregnancy had significantly lower bone mineral content ( BMC ) , bone area ( BA ) , and bone mineral density ( BMD ) at the hip throughout 12 mo lactation ( mean ± SE difference : BMC = −10.7 ± 3.7 % , P = 0.005 ; BA = −3.8 ± 1.9 % , P = 0.05 ; BMD = −6.9 ± 2.6 % , P = 0.01 ) . The women also experienced greater decreases in bone mineral during lactation at the lumbar spine and distal radius and had biochemical changes consistent with greater bone mineral mobilization . Conclusions : Calcium supplementation  in pregnant women with low calcium intakes may disrupt metabolic adaptation and may not benefit maternal bone health . Further study is required to determine if such effects persist long term or elicit compensatory changes in bone structure Maternal vitamin D deficiency during pregnancy is a recognized risk factor for rickets and osteomalacia in infancy ( 1 ) . The circulating plasma concentration of 25-hydroxyvitamin D ( 25OHD ) , a long-lived metabolite of vitamin D , is used to judge vitamin D status ; values below 25 nmol/L are associated with an increased risk of rickets and osteomalacia ( 1 ) . There is evidence that a low maternal plasma 25OHD in pregnancy may influence the growth and bone mineral accrual of the offspring during foetal life , infancy and childhood . Positive associations have been reported between maternal  vitamin D  status in pregnancy and birthweight , birth length , length at 1 year and bone mineral accretion at 9 years ( 2–6 ) , although evidence is conflicting ( 7,8 ) . These relationships have been observed at concentrations of 25OHD higher than those associated with rickets and osteomalacia , and there are calls to raise the accepted lower threshold of vitamin D sufficiency for pregnant women , most recently to 80 nmol/L ( 9 ) . On a population basis , plasma 25OHD concentrations above 80 nmol/L are relatively uncommon in countries at temperate latitudes but are more common among people living in the tropics who have abundant skin sunshine exposure ( 10 ) . To contribute to the debate on the definition of vitamin D sufficiency in pregnancy , we have investigated the influence of maternal plasma 25OHD concentration on foetal and infant growth in a rural area of The Gambia , West Africa ( 13 ° N ) . In this region , there is tropical sunshine all year , the women are farmers who work out-of-doors for much of each day , and local female dress does not restrict regular sunshine exposure to the face , neck , shoulders , arms and feet , especially during farm work and gardening . The study was a secondary analysis of biochemical , anthropometric and bone data from a subset of 125 women and infants collected during a calcium supplementation study of blood pressure in pregnant Gambian women ( International Trial Registry : IS RCT N96502494 ) . No significant benefits for foetal and infant growth of maternal calcium supplementation were identified despite the low customary calcium intake in The Gambia ( 11 ) . The protocol , methods , maternal characteristics and infant data from the detailed study have been published ( 11 ) . Briefly , women from the rural villages of Keneba and M and uar , West Kiang , The Gambia were recruited at 20 weeks of pregnancy ( P20 ) and r and omized to a daily calcium supplement or a matching placebo tablet until parturition ( 1500 mg Ca as calcium carbonate and microcellulose-lactose , respectively ; Nycomed Pharma AS , Asker , Norway ) . Fasting , early morning blood was collected and anthropometry performed at P20 and 36 weeks of pregnancy ( P36 ) . The mean ( ± SD ) age , weight , height and dietary calcium intake of the women at P20 were 27.4 ± 7.5 years , 56.3 ± 6.7 kg , 1.61 ± 0.05 m and 356 ± 190 mg/day , respectively . The median parity ( range ) was 3 ( 0–10 ) . Infant birthweight was measured within 24 h of delivery . Weight , crown-heel length and head circumference were measured at 2 , 13 and 52 weeks postpartum . In addition , infant bone mineral content ( BMC ) , bone mineral density ( BMD ) and bone width ( BW ) or bone area ( BA ) , were measured by single photon absorptiometry of the midshaft radius ( Lunar SP2 , Lunar Corporation , Madison , WI , USA ) and , for a subset ( n = 44 , 47 and 52 at 2 , 13 and 52 weeks , respectively ) , by whole-body dual-energy X-ray absorptiometry ( Lunar DPX+ , software version 4.7b , Lunar Corporation ) . Plasma 25OHD was measured a using radioimmunometric assay ( Diasorin Ltd , Wokingham , Berks , UK ) , with assay performance monitored through the Vitamin D External Quality Assessment Scheme ( DEQAS ; Endocrine/Oncology Laboratory , Charing Cross Hospital , London , UK ) . The intra- and inter-assay coefficients of variation were 4 % and 100 ) ; possible trends in the data with p = 0.01–0.1 were noted . The analysis was conducted on 123 mother – infant pairs ; blood sample s from two subjects were not available . Mean ± SD 25OHD ( range ) was : P20 = 103 ± 25 ( 53–167 ) nmol/L ; P36 = 111 ± 27 ( 51–189 ) nmol/L. No subject had a 25OHD value < 50 nmol/L , 20 % and 16 % had 25OHD < 80 nmol/L , at P20 and P36 , respectively . There was a high degree of within-subject consistency in 25OHD at P20 and P36 ( 25OHDP36 = 33.2 + [ 0.79 ± 0.07] × 25OHDP20 , p ≤ 0.001 , R2 adjusted 51.5 % , n = 121 ) ; 11 % of women had 25OHD < 80 nmol/L at both P20 and P36 . The mean birthweight of the infants was 2.99 ± 0.36 kg . The infant anthropometric and bone measures during the first year are given in Table 1 . No significant relationships or trends in the data were observed between maternal 25OHD concentration using the values at P20 , P36 or the mean of the two and any of the following infant measures : birthweight , infant weight , length , head circumference , BMC , BW ( or BA ) , BMD and size-adjusted BMC of the midshaft radius and whole body at any time postpartum . This is illustrated in Figure 1 for birthweight as a function of maternal 25OHD concentration at P20 . Comparing the results for mothers with 25OHD above and below 80 nmol/L did not alter this finding . Table 1 Anthropometric and bone measures  of Gambian infants Figure 1 Lack of a significant relationship between infant birthweight and maternal vitamin D status at 20 weeks of pregnancy ( p = 0.8 ) . Multiple regression model included season , maternal height , weight , weight gain , supplement group and sex of the infant . No significant interaction between supplement group and maternal 25OHD concentration was observed for any infant variable . Trends in the data were observed in a few instances for a supplement group × 25OHD interaction among the bone measures but no consistent picture emerged and they were considered to have arisen by chance . We conclude that there is no evidence for an influence of vitamin D status during pregnancy on infant growth and bone mineral accrual in the conditions prevailing in The Gambia . The children in this study , as is common in this region of The Gambia ( 13 ) , were born small , grew well for the first months of life but experienced growth faltering during later infancy compared to Western children ( 11,14 ) , as demonstrated by their weight and length SDS . The 25OHD concentrations of the women were > 50 nmol/L in the second half of pregnancy , and no distinction could be drawn in infant outcomes between mothers with concentrations above or below 80 nmol/L. Thus , our study suggests that , for women with regular , adventitious UVB sunshine exposure and in situations where foetal and infant growth may be constrained by multiple factors , there would be no benefit for foetal and infant growth or bone mineral accrual in aim ing to increase the vitamin D status of individual mothers during pregnancy above 50 or 80 Context Some data suggest that body weight is inversely associated with calcium intake , increasing the possibility that supplemental calcium might facilitate weight loss or prevent weight gain . Contribution Research ers r and omly assigned overweight and obese patients to supplemental calcium or placebo and found no between-group differences in measures of weight change . Caution Trial participants were almost all women . Implication Calcium supplementation is unlikely to prevent weight gain in persons who are overweight or obese . The Editors The high prevalence of overweight and obesity in the United States ( 1 ) has stimulated great interest in identifying approaches that may help to prevent weight gain or improve ability to lose weight . Increasing calcium intake is a potential means of weight management that has received much attention from both lay press ( 24 ) and the medical community ( 57 ) . This interest has been stimulated by a series of cross-sectional studies ( 817 ) reporting that children and adults with low reported consumption of dietary ( primarily dairy ) calcium  have greater body weight , a higher degree of adiposity , and greater risk for having components of the metabolic syndrome than those who report that they consume more calcium . Some ( 1824 ) , although not all ( 2534 ) , longitudinal investigations have also suggested that children and adults who consume a lower calcium diet tend to gain more weight than those with greater dietary or supplemental calcium intake . These data , together with some small clinical trials suggesting that weight loss during dieting may be augmented by supplemental ( 35 ) or dairy calcium ( 3538 ) , have led to expectations that substantially augmenting calcium intake might diminish body weight by 0.5 kg or more each year ( 5 , 18 , 22 , 39 ) . Two possible mechanisms for an effect of dietary calcium on body weight have been suggested . First , calcium can combine with fatty acids in the intestine to form insoluble soaps that are therefore not absorbed ( 40 , 41 ) . Second , some research ers ( 4246 ) have proposed that low dietary calcium leads to increased adipocyte triglyceride deposition ( 4749 ) . If calcium substantially affects fat accumulation , calcium supplementation could prevent additional weight and fat gain among people with high body weight . To test this hypothesis , we measured the effect of calcium carbonate supplementation for 2 years on the weight and body fat of overweight and obese adults . Methods Setting and Participants We recruited participants through advertisements posted in Bethesda , Maryl and , and spontaneous reply to newspaper and radio advertising in the Washington , DC , metropolitan area seeking healthy adult volunteers for a project to study the health effects of calcium supplementation . Men and women age 18 to 80 years were eligible to enroll if they had a body mass index ( BMI ) of 25 kg/m2 or more and did not have cerebrovascular , cardiovascular , pulmonary , renal , hepatic , endocrinologic , or other substantial medical disease . Women were ineligible if they were pregnant , were breastfeeding , or had received a recommendation from a health care professional to take calcium supplements for any condition . We excluded persons who regularly used medications known to affect body weight , had a weight loss of 3 % or more in the preceding 3 months , reported total calcium intake in excess of 3.5 g/d , used supplemental calcium in excess of 300 mg/d , used vitamin D supplements in excess of 400 IU/d , or had a history of renal stones . The institutional review board of the National Institute of Child Health and Human Development , National Institutes of Health , approved the research protocol . Each participant provided signed consent . We provided financial compensation for participants ' time and inconvenience . Design Overview We conducted a single-center , r and omized , double-blind , placebo-controlled trial from March 2002 to April 2006 . After an outpatient visit to determine eligibility and obtain initial assessment s , participants entered a 2-year , double-blind treatment period . R and omization and Interventions We r and omly assigned participants , in a 1:1 ratio , to receive either elemental calcium , 1500 mg/d ( calcium carbonate , purchased from Particle Dynamics , St. Louis , Missouri ) , or placebo , administered as 2 divided doses with meals . Investigators assigned consecutive code numbers to participants from prespecified lists stratified by race or ethnicity , sex , and BMI ( 25 to 26.99 , 27 to 29.99 , 30 to 34.99 , and 35 kg/m2 ) . The National Institutes of Health Clinical Center Pharmaceutical Development Section used permuted blocks with stratification to generate the allocations that translated code numbers into study group assignments by using a pseudo-r and om number program . The Pharmaceutical Development Section prepared placebo and calcium capsules to appear identical . Pharmacy personnel , not otherwise involved with the conduct of the study , dispensed study capsules with medication placed in containers that appeared identical and differed only by the individual participant code number . No participant , investigator , or other medical or nursing staff interacting with participants was aware of study group assignments for the duration of the trial . Initial Assessment At their prer and omization evaluation , participants reported after an overnight fast and were weighed in hospital gowns by using a digital scale ( Life Measurement Instruments , Concord , California ) that was calibrated with a known weight before each participant 's measurement . We measured height by using a stadiometer calibrated before each measurement ( Holtain , Crymych , United Kingdom ) . Research dietitians assessed abdominal and hip circumferences in triplicate to the nearest 0.1 cm , as recommended ( 50 , 51 ) , and measured triceps skinfold thickness to the nearest 0.5 mm by using Lange calipers ( Cambridge Scientific Industries , Cambridge , Maryl and ) . We measured blood pressure , obtained after a 5-minute rest period , 3 times at 5-minute intervals from seated participants by using an automated sphygmomanometer ( Dinamap-Plus , Critikon , Tampa , Florida ) . We did whole-body dual-energy x-ray absorptiometry to estimate total body fat mass ( Delphi A , software version 11.2 , Hologic , Bedford , Massachusetts ) . We measured intact parathyroid hormone concentrations with 2-site immunochemiluminometric assays ( 52 ) , and serum 25-hydroxy vitamin D levels by using a competitive binding assay ( Nichols Advantage , Nichols Diagnostic , San Clemente , California ) ( 53 ) . We asked participants with substantial vitamin D deficiency ( serum 25-hydroxy vitamin D level < 25.0 nmol/L ) to take vitamin D , 400 IU/d ( ergocalciferol ) , in a multivitamin . We assessed baseline dietary calcium intake by using a 7-day food record that a registered dietitian review ed with each participant to maximize accuracy and completeness , and analyzed for dietary calcium intake by using the Nutrition Data System for Research software , versions 4.04_32 and 4.05_33 ( University of Minnesota , Minneapolis , Minnesota ) ( 54 ) . We measured calcium intake from multivitamins or calcium supplements with a vali date d calcium question naire ( 55 ) that was review ed for completeness through an interview with a registered dietitian . We recorded the calcium content as it was listed on the label of each multivitamin or calcium supplement . We measured dietary and supplemental vitamin D intakes in the same manner . We estimated energy intake at baseline and at 2 years by using a food-frequency question naire that assessed total diet ( 5557 ) . We measured socioeconomic status by using the Hollingshead score ( 58 ) . Outcomes and Follow-up Primary efficacy end points were change in body weight and body fat mass at the end of 2 years of treatment . Secondary outcomes were fasting anthropometric measurements , body composition by dual-energy x-ray absorptiometry , and change in blood pressure , assessed yearly , along with question naire data on dietary and supplemental calcium intake ( 55 ) . In addition , we contacted participants every 3 months to complete question naires about their adherence to the medication regimen ; assess their general health ; and obtain self-reports of mood , stress , physical activity , and hunger . Every 6 months , participants returned to the clinic to exchange their unused study medication for a new supply . We used the tally of returned capsules to assess adherence . To examine adequacy of the masking procedure , participants completed a question naire at the end of the study that requested they report their best guess about their study group assignment . Statistical Analysis All reported primary data analyses were prespecified . On the basis of our previous study of observed yearly changes in body weight over time ( 59 ) , we needed a total sample size of 256 participants to detect a 0.35-kg difference per year in weight change ( that is , 0.7 kg over 2 years ) between groups with 80 % power . Participant accrual was set at 340 participants to allow 25 % loss to follow-up . We analyzed data by using SPSS for Windows , version 14.0 ( SPSS , Chicago , Illinois ) . We assessed efficacy in the intention-to-treat sample of all r and omly assigned participants . We did 2 efficacy analyses . The primary analysis used a multiple imputation model for missing data under a missing-at-r and om assumption ( 60 ) . By using NORM , version 2.03 ( The Pennsylvania State University , State College , Pennsylvania ) ( 61 , 62 ) , we included all available baseline , 1-year , and 2-year outcome measures in an imputation model along with age , sex , race , baseline serum 25-hydroxy vitamin D concentration , baseline calcium intake , and study group . We then combined the coefficients from analyses of 20 imputed data sets into a single set of estimates according to Shafer ( 62 ) and the Rubin rules ( 63 ) . To assess sensitivity of these results to the missing-at-r and om assumption , we conducted 3 additional analyses : assuming that all participants who withdrew from the study had major weight gain ( Objective To determine whether increased calcium intake ( 2 g/day ) in pregnancy is effective in reducing the risk of preeclampsia in pregnant teenagers . Methods The present study was a prospect i ve , r and omized , double-blind , controlled clinical trial . Two hundred sixty teenaged pregnant girls attending the Hospital Gíneco-Obstétrico Isidro Ayora in Quito , Ecuador , were included . Selection criteria were age less than 17.5 years , nulliparity , first prenatal visit before 20 weeks ' gestation , and residency in Quito ( 2800-m altitude ) . We used a table of r and om numbers to assign 125 girls to receive 2000 mg of elemental calcium daily , beginning at 20 weeks of gestation and continuing until delivery ; 135 women in the control group received a placebo .  Blood pressure ( BP ) was measured twice every 4 weeks until delivery and at 48 hours after delivery . The diagnosis of preeclampsia was defined as BP greater than 140/90 mmHg on at least two occasions more than 6 hours apart and proteinuria greater than 30 mg/dL ( over one cross by dipstick on two occasions 4 - 24 hours apart ) . Results The average daily calcium intake in this population was approximately 51 % of the Recommended Dietary Allowance . Calcium supplementation was associated with a significantly decreased risk of preeclampsia ( risk reduction 12.35 % ; P < .001 ) , with 3.2 % ( n = 4 ) developing preeclampsia in the treatment group versus 15.5 % ( n = 21 ) in the placebo group . Moreover , calcium supplementation led to a reduction in systolic BP of 9.1 mmHg and in diastolic BP of 6.0 mmHg . Conclusion These results suggest that calcium supplementation during pregnancy in population s with low calcium intake is a safe , effective , and inexpensive preventive measure that significantly reduces the risk of preeclampsia Results are presented of a r and omized , double-blinded controlled clinical trial of calcium supplementation ( 2.0 gm of elemental calcium as calcium carbonate ) and a placebo .  All participants were 17 years of age or less and clinical ly healthy . Patients were enrolled by the twenty third week of gestation . The mean duration of calcium supplementation or placebo was approximately 14 weeks . Treatment consisted of 2.8 ( + /- 1.5 ) tablets per day in the placebo group ( N = 95 ) and 3.0 ( + /- 1.4 ) tablets per day in the calcium group ( N = 94 ) . Dietary calcium intake was similar in both groups at about 1200 mg/day . The calcium group had a lower incidence of preterm delivery ( less than 37 weeks ; 7.4 % vs 21.1 % ; p = 0.007 ) ; spontaneous labor and preterm delivery ( 6.4 % vs 17.9 % ; p = 0.01 ) ; and low birth weight ( 9.6 % vs 21.1 % ; p = 0.03 ) . This effect was also present after stratified analysis by level of treatment compliance , urinary tract infection , and chlamydial infection . Life-table analysis demonstrated an overall shift to a higher gestational age in the calcium group compared with the placebo group ( log-rank test , p = 0.02 ) . As suggested previously , the observed effect could be mediated by a reduction in uterine smooth muscle contractibility . If confirmed by future research , these results could represent an important preventive intervention for prematurity in high-risk population Objective To evaluate the efficacy of oral supplemental calcium in reducing the incidence of pregnancy-induced hypertension ( gestational hypertension or preeclampsia ) in angiotensin-sensitive nulliparas OBJECTIVE : To evaluate the effects of dietary calcium ( Ca ) intervention on adolescent pregnant mothers and their newborns . METHODS : Seventy-two pregnant adolescent mothers were r and omized into one of 3 groups : control , orange juice fortified with calcium , and dairy . The orange juice and dairy groups were required to take more than 1,200 mg Ca . Calcium tablets were added for those not able to meet required Ca . Maternal and infant weight , length , and blood pressure ( BP ) were recorded . Maternal dietary records were evaluated . Mother ’s blood was drawn for serum Ca , phosphate ( P ) , magnesium ( Mg ) , and vitamin 25-hydroxyvitamin D ( D ) . Cord blood was collected for serum Ca and D. Newborn total body Ca was determined . RESULTS : All mothers were similar in weight , height , and BP . Mothers in the orange juice plus calcium and dairy groups had higher intakes of Ca ( 1,472 mg and 1,771 mg ) than controls ( 862 mg ) . One half of the mothers in the orange juice plus calcium group required Ca tablets . Mothers in the dairy group had higher intakes of P , D , and Mg , higher serum folate and D , and higher cord D levels . Mothers in the orange juice plus calcium group had higher serum P but lower serum folate and D. Infants ( 3,517±273 g ) in the dairy group were heavier than infants in the control ( 3,277±177 g ) and orange juice plus calcium ( 3,292±165 g ) groups . Infants in the dairy group had higher total body calcium than control infants . CONCLUSION : Calcium diet supplemented with dairy products during adolescent pregnancy result ed in higher maternal vitamin D and folate serum levels and higher newborn weight and bone mineralization compared with controls . CLINICAL TRIAL REGISTRATION : Clinical Trials.gov , www . clinical trials.gov , NCT00320125 LEVEL OF EVIDENCE : OBJECTIVE The purpose of this trial was to determine whether calcium supplementation of pregnant women with low calcium intake reduces  preeclampsia and preterm delivery . STUDY DESIGN R and omized placebo-controlled , double-blinded trial in nulliparous normotensive women from population s with dietary calcium < 600 mg/d . Women who were recruited before gestational week 20 received supplements ( 1.5 g calcium/d or placebo ) throughout pregnancy . Primary outcomes were preeclampsia and preterm delivery ; secondary outcomes focused on severe morbidity and maternal and neonatal mortality rates . RESULTS The groups comprised 8325 women who were assigned r and omly . Both groups had similar gestational ages , demographic characteristics , and blood pressure levels at entry . Compliance were both 85 % and follow-up losses ( calcium , 3.4 % ; placebo , 3.7 % ) . Calcium supplementation was associated with a non-statistically significant small reduction in preeclampsia ( 4.1 % vs 4.5 % ) that was evident by 35 weeks of gestation ( 1.2 % vs 2.8 % ; P = .04 ) . Eclampsia ( risk ratio , 0.68 : 95 % CI , 0.48 - 0.97 ) and severe gestational hypertension ( risk ratio , 0.71 ; 95 % CI , 0.61 - 0.82 ) were significantly lower in the calcium group . Overall , there was a reduction in the severe preeclamptic complications index ( risk ratio , 0.76 ; 95 % CI , 0.66 - 0.89 ; life-table analysis , log rank test ; P = .04 ) . The severe maternal morbidity and mortality index was also reduced in the supplementation group ( risk ratio , 0.80 ; 95 % CI , 0.70 - 0.91 ) . Preterm delivery ( the neonatal primary outcome ) and early preterm delivery tended to be reduced among women who were < or = 20 years of age ( risk ratio , 0.82 ; 95 % CI , 0.67 - 1.01 ; risk ratio , 0.64 ; 95 % CI , 0.42 - 0.98 , respectively ) . The neonatal mortality rate was lower ( risk ratio , 0.70 ; 95 % CI , 0.56 - 0.88 ) in the calcium group . CONCLUSION A 1.5-g calcium/day supplement did not prevent preeclampsia but did reduce its severity , maternal morbidity , and neonatal mortality , albeit these were secondary outcomes In a r and omized controlled trial 201 healthy nulliparous women were r and omly allocated by means of a computer generated r and omization list . From 20 weeks of gestation until delivery they received either 2 g of oral elemental calcium ( n = 103 ) per day or an identical placebo ( n = 98 ) . Eleven women ( 5.47 % ) were lost to follow-up after r and omization . The study groups were very similar at the time of r and omization ; with respect to several clinical and demographic variables . Treatment compliance was very similar in both groups as was determined by pill count . The rate of pregnancy induced hypertension was lower in the calcium group than in the placebo group 8.24 % ; vs 29.03 % ; ( RR = 0.28 ; 95 % CI 0.14 - 0.59 ) . The incidence of gestational hypertension was 6.18 % in the calcium group and 17.20 % in the placebo group ( RR = 0.28 ; 95 % CI 0.08 - 0.80 ) , and the incidence of preeclampsia was 2.06 % in the calcium group and 11.82 % in the placebo group ( RR = 0.13 ; 95 % CI 0.01 - 0.64 ) . In conclusion calcium supplementation given in pregnancy to nulliparous women reduces the incidence of pregnancy induced hypertension In this study the hypothesis that calcium supplementation during pregnancy can modify blood pressure patterns in a population of normal pregnant women was tested . Thirty-six women with normal single pregnancies , between 20 and 35 years of age , in the second trimester of gestation ( 15 weeks ) , were r and omly assigned to receive 1 gm of calcium per day ( n = 11 ) , 2 gm per day ( n = 11 ) , or a placebo ( n = 14 ) . No differences were observed at the times of admission into the study ( baseline ) in demographic and clinical variables or in the calcium intake of each group . Baseline blood pressure measures in several positions also were not different . After the initial blood pressure measures ( fifteenth week ) , five follow-up blood pressure measures were obtained . The supplemented groups had significantly lower diastolic blood pressure than the control subjects between the twentieth and twenty-fourth weeks of gestation . Thereafter , an increase in the control group and the group receiving 1 gm of calcium was observed , but levels were similar at term . On the contrary , patients receiving 2 gm of calcium had blood pressure values that remained significantly lower throughout the third trimester . No differences or clear patterns were observed in the blood levels of calcium , magnesium , phosphorus , and proteins between and within groups during gestation . A possible explanation involving parathyroid hormone is attempted Objective Calcium dem and is increased during pregnancy . However , few r and omized controlled trials examined the effects of calcium supplementation on bone mass during pregnancy . This study determined effects of calcium and milk supplementation on maternal bone mineral density ( BMD ) and bone turnover in pregnant Chinese women with habitual low calcium intake . Methods In this r and omized controlled trial , 36 Chinese pregnant women ( 24–31 years , 18 gestational weeks ) were r and omly assigned to the following three arms ( 12 each ) : I , usual diet ; II , “ I ” + 45 g milk powder ( containing 350 mg calcium ) ; or III , “ II ” + 600 mg calcium/day from gestational age of 20 weeks to 6 weeks post-partum ( PP ) . BMD was measured post-treatment using dual-energy X-ray absorptiometry . Dietary intakes , 24-h urinary calcium , bone resorption ( urinary hydroxyproline ) and formation ( serum osteocalcin ) biomarkers were examined at the gestational age of 20 and 34 weeks , and 6 weeks PP . Results A dose-dependent relationship was observed between calcium intake and BMDs . The BMD values were significantly higher in subjects with calcium and milk supplementation  than those in the controls at the whole body and spine ( p < 0.05 ) but not at the hip sites . We found significant decreases in changes of urinary hydroxyproline , and significant increases in serum osteocalcin during the intervention period in the calcium/milk intervention groups than those in the control group ( all p < 0.05 ) . Conclusion Calcium/milk supplementation during pregnancy is associated with greater BMD at the spine and whole body and suppresses bone resorption in Chinese women with habitual low calcium intake OBJECTIVE We postulated that calcium supplementation of calcium-deficient pregnant women would lower vascular resistance in uteroplacental and fetoplacental circulations . STUDY DESIGN Pulsatility index ( PI ) and resistance index ( RI ) ( uterine and umbilical arteries ) and presence of bilateral uterine artery diastolic notching were assessed by Doppler ultrasound between 20 - 36 weeks ' gestation in 510 healthy , nulliparous Argentinean women with deficient calcium intake in a r and omized , placebo-controlled , double-blinded trial . RESULTS Average umbilical and uterine artery RI and PI tended to be lower in the supplemented group at each study week . Differences became statistically significant for umbilical artery RI and PI from 32 and 36 weeks , respectively . Estimated probabilities of bilateral uterine artery diastolic notching trended toward lower values in calcium-supplemented women . CONCLUSION Calcium supplementation of pregnant women with deficient calcium intake may affect uteroplacental and fetoplacental blood flow by preserving the vasodilation of normal gestation The results of ten clinical trials suggest that supplemental calcium may prevent  preeclampsia .  However , method ologic problems and differences in study design limit the acceptance of the results and their relevance to other patient population s. Many of the trials were conducted in countries where , unlike the United States , the usual daily diet contained little calcium . Moreover , none of the trials has reported the outcome of systematic surveillance for urolithiasis , a potential complication of calcium supplementation . In response to the need for a thorough evaluation of the effects of calcium supplementation for the prevention of preeclampsia in the United States , the trial of Calcium for Preeclampsia Prevention ( CPEP ) was undertaken at five university medical centers . Healthy nulliparous patients were r and omly assigned to receive either 2 g supplemental calcium daily  ( n = 2295 ) or placebo  ( n = 2294 ) in a double-blind study . Study tablets were administered beginning from 13 to 21 completed weeks of gestation and continued until the termination of pregnancy . CPEP employed detailed diagnostic criteria , st and ardized techniques of measurement , and systematic surveillance for the major study endpoints and for urolithiasis . The nutrient intake of each patient was assessed at r and omization and at 32 - 33 weeks gestation . This report describes the study rationale , design , and methods OBJECTIVE To research some effects of different levels of calcium intake in the mother 's bone mineral density . METHODS On the basis of insignificantly different among energy and other nutrition intake excepting calcium , 35 volunteers in pregnant 18 weeks healthy women were r and omly divided into I. II and III group [ calcium intake were ( 550 + /- 150 ) mg/d , ( 900 + /- 150 ) mg/d and ( 1,500 + /- 150 ) mg/d ] . The tracked study began from pregnant 20 weeks to postpartum 45 days . All over and different body of BMD ( Bone Mineral Density ) were assessed by dual-energy X-rays absorptiometry . RESULTS I group of many location BMD were below that of other groups ( P < 0 . 01 ) . As compared with the same age women 's lumbar spine BMD , I group was only maintained within the rang ( 85.14 + /- 6.61)% , and osteoporosis in some places of bone were found in some individual . II group was ( 90.74 + /- 6.53)% . III group was ( 100.44 + /- 5.19)% . Allover different body 's BMD were significantly correlated with the average BMD ( r > 0.8 , P < 0.1 ) , the most significant correlation was third lumbar spine . Calcium intake of women was positively correlated with different body 's BMD ( r > 0.5 , P < 0.01 ) . CONCLUSION III group , calcium intake was ( 30.68 + /- 3.56 ) mmol/d , pass through period of pregnancy , parturition and short-term breast-feed mother body remain the same BMD , and prevent osteoporosis . Reporting pregnant women calcium nutrition pass through BMD , lumbar spine is good representation OBJECTIVE To study the effect of calcium supplementation on reduction of pre-eclampsia in Iranian women at high risk of pre-eclampsia . METHODS Thirty pregnant women at high risk of developing pre-eclampsia were r and omized to 2 g of daily calcium and placebo . Subjects and investigators were blinded to treatment allocation . The inclusion criteria were positive rollover test , having at least one risk factor for pre-eclampsia , between 28 and 32 weeks of pregnancy , and blood pressure less than 140/90 ( mm Hg ) . Exclusion criteria were having any chronic condition . Pre-eclampsia was defined as systolic/diastolic blood pressure over 140/90 plus proteinuria . All the subjects were followed up to delivery . RESULT A sevenfold reduction in the occurrence of pre-eclamsia were seen among the calcium group compared with the placebo group ( 7 out of 15 developed pre-eclampsia in control group vs. 1 out of 15 in calcium group , P=0.014 ) . No major effect on pregnancy induced hypertension was seen ( 66 % in placebo and 76 % in calcium group developed hypertension ) but the onset of hypertension was delayed 3 weeks in the calcium group . A longer duration of pregnancy was seen in calcium than placebo ( mean+/-S.D.=37+/-2 for calcium and 34+/-2 for placebo , P<0.05 ) . Infants born to the calcium group , on average , were 552 g heavier than infants born to the placebo group , P<0.05 . CONCLUSION Calcium supplementation is beneficial for preventing pre-eclampsia among Iranian women at high risk of developing pre-eclampsia Objective To determine whether calcium supplementation prevents progression to severe disease in preterm nulliparous women with mild preeclampsia . Methods Seventy-five women hospitalized at 24–36 weeks ' gestation because of mild preeclampsia were r and omized to receive either 2 g/day of elemental calcium ( 36 women ) or placebo ( 39 ) . Both groups had similar demographic characteristics , initial blood pressure measurements , and amount of proteinuria . Diagnostic criteria and clinical management for severe preeclampsia were applied consistently . Results Eighteen of 36 calcium-treated subjects ( 50 % , 95 % confidence interval [ CI ] 33–67 ) developed severe preeclampsia , compared with 19 of 39 ( 48.7 % , 95 % CI 32–65 ) in the placebo group ( relative risk 1.03 , 95 % CI 0.64–1.03 ; P = 1.00 ) . Blood pressure values , gestational age at delivery , newborn weights , incidence of low Apgar scores , and umbilical arterial blood gases were similar for the two groups . Conclusion Calcium supplementation does not prevent severe preeclampsia in preterm patients with mild disease Based on cell culture and studies in mice , increased dietary calcium appears to stimulate lipolysis and could possibly reduce body adiposity through hormonal influences on adipocyte calcium uptake . In this study , we investigated the effects of 1,500 mg supplemental calcium daily for 3 months on hormones regulating calcium and energy metabolism and rates of lipid oxidation and lipolysis in overweight women . Fifteen overweight ( BMI > 25 kg/m(2 ) ) premenopausal women were supplemented with 1,500 mg of calcium , as CaCO(3 ) , per day for 3 months while maintaining their usual diets and activity levels . Baseline and endpoint measurements were obtained after the subjects consumed a st and ardized 25 % fat diet for 4 days . Lipid oxidation was measured by indirect calorimetry , lipolysis by infusion of deuterated glycerol , and body fat by dual-energy X-ray absorptiometry . Urinary calcium , circulating levels of hormones involved in energy and lipid metabolism ( insulin , leptin , and adiponectin ) or calcium metabolism ( 25(OH)D , 1,25(OH)(2)D ) , and parathyroid hormone ( PTH ) ) were also measured . Urinary levels of calcium ( P = 0.005 ) increased and 1,25(OH)(2)D declined ( P = 0.03 ) . However other parameters , including body weight , body fat , PTH , insulin , leptin , adiponectin , 25(OH)D , as well as rates of lipid oxidation and lipolysis were not altered by calcium supplementation . Calcium supplementation for 3 months increased urinary calcium excretion , decreased circulating levels of 1,25(OH)(2)-D , but had no effect on rates of lipid oxidation or lipolysis , in these overweight women OBJECTIVE The objectives of the study were to confirm the validity of using oscillometric measurement of MAP in the left lateral position to identify those at high risk for developing pregnancy-induced hypertension ( PIH ) , and to assess and compare the efficacy of prophylaxis with low-dose aspirin or calcium supplementation in high-risk patients . STUDY DESIGN A prospect i ve study in pregnancy ; 500 normotensive , primigravid Chinese women were recruited in the second trimester of pregnancy on the basis of 80 mm Hg > or = MAP < 106 mm Hg in the antenatal clinic . They were then screened by Dinamap in a research setting , measuring MAP in the left lateral position after rest and using a cutoff value of 60 mm Hg for inclusion in the r and omized study . R and omization was divided into three groups : control , low-dose aspirin , and calcium supplementation . After delivery , patients were classified as either having remained normotensive or having developed PIH , with or without proteinuria . RESULTS The incidence of both proteinuric and nonproteinuric PIH was significantly lower in patients screened out as low risk than in those selected as high risk using a critical value of 60 mm Hg for left lateral MAP ( p < 0.05 ) . The incidence of proteinuric PIH was significantly lower in patients given low-dose aspirin than in the control group ( p < 0.05 ) . However , the confidence intervals for the effect were wide , comparable with aspirin having no effect or leading to a 16-fold reduction in the risk of preeclampsia . For those given calcium supplementation , the reduction was not significant . There was no significant difference in the incidence of nonproteinuric PIH between the control group and the two groups receiving prophylaxis . CONCLUSION Oscillometric measurement of second-trimester left lateral MAP is a valid predictor of proteinuric PIH . Low-dose aspirin may offer a degree of protection from proteinuric PIH in these high-risk women . Calcium supplementation was not shown to significantly reduce the incidence of PIH We investigated the inhibitory effect of calcium on  iron absorption in 57 human subjects . Three studies suggested that the effect is not located in the gastrointestinal tract . The presence of phytate in a meal and formation of calcium-iron-phytate complexes is not a prerequisite for the inhibition . The relative increase in iron absorption by ascorbic acid was the same in meals with and without calcium , suggesting that calcium did not influence the balance between enhancing and inhibiting lig and s in the gastrointestinal lumen . No inhibiting effect on iron absorption was seen when adding 3 mg calcium to 0.01 mg iron ( molar ratio Ca/Fe = 420 ) . Previous studies showing a marked inhibition by calcium had a lower molar ratio , but greater amounts of calcium were given . This suggests that a minimal concentration of calcium is needed to achieve an effect . The present results indirectly support our original hypothesis that the inhibitory effect of calcium on iron absorption is situated within the intestinal mucosal cells . The practical nutritional implication s of the inhibitory effect of calcium are considerable since addition of milk , milkshake or cheese to common meals such as pizza or hamburger meals reduced iron absorption by 50 - 60 % . It is recommended to reduce the intake of dairy products with the main meals providing most of the dietary iron , especially for those having the highest iron requirements i.e. children , teenagers and women at childbearing age Following our detailed studies of human milk calcium concentration , we hypothesized that calcium intake in pregnancy may determine human milk calcium concentration and hence the calcium intake of breastfed infants ( Prentice et al. 1994 ) . To test this , we conducted a controlled calcium supplementation study in pregnant women accustomed to a low calcium intake Abstract Objective : To explore the long term effect of calcium supplementation during pregnancy on the offspring 's blood pressure during childhood . Design : Follow up of a population enrolled in a double blind , r and omised , placebo controlled trial . Setting : Perinatal research unit , World Health Organisation 's collaborative research centre . Subjects : 591 children at a mean age of 7 years whose mothers were r and omly assigned during pregnancy to receive 2 g/day of elemental calcium ( n=298 ) or placebo ( n=293 ) . Main outcome measures : Mean blood pressure and rate of high blood pressure of children . Results : Overall , systolic blood pressure was lower in the calcium group ( mean difference -1.4 mm Hg ; 95 % confidence interval -3.2 to 0.5 ) than in the placebo group . The effect was found predominantly among children whose body mass index at assessment was above the median for this population ( mean difference in systolic blood pressure -5.8 mm Hg ( -9.8 mm Hg to -1.7 mm Hg ) for children with an index > 17.5 and -3.2 mm Hg ( -6.3 mm Hg to -0.1 mm Hg ) for those with an index of > 15.7 to 17.5 ) . The risk of high systolic blood pressure was also lower in the calcium group than in the placebo group ( relative risk 0.59 ; 0.39 to 0.90 ) and particularly among children in the highest fourth of body mass index ( 0.43 ; 0.26 to 0.71 ) . Conclusion : Calcium supplementation during pregnancy is associated with lower systolic blood pressure in the offspring , particularly among overweight children . Key messages Impaired fetal and maternal nutrition seem to be associated with childhood blood pressure , but most of the evidence comes from uncontrolled studies Systolic blood pressure of children aged between 5 and 9 years was lower when mothers took calcium rather than placebo during pregnancy The effect is found predominantly among children with a body mass index above the median for this population Fetal life seems to be a period for programming blood pressure ; the magnitude of the effect observed has health implication s among overweight Summary . Previous studies have suggested that increased dietary calcium is associated with a decreased occurrence of pregnancy‐induced hypertension  . In this study 106 young healthy nulliparous women , residing in Quito , Ecuador , were enrolled in a double‐blind , r and omized , controlled clinical trial . From 24 weeks gestation until delivery they received either 2 g of elemental calcium per day or a placebo . Calcium supplementation was associated with a significantly decreased risk of pregnancy‐induced hypertension , with 4.1 % developing pregnancy‐induced hypertension in the treatment group versus 27.9 % in the placebo group . Treatment was associated with a decrease in both systolic and diastolic blood pressure over the course of pregnancy . In addition , there was a small but significant increase in serum ionized calcium levels in the calcium‐supplemented group during the treatment period BACKGROUND Maternal nutritional intake during pregnancy may have important consequences for long-term health in offspring . OBJECTIVE The objective was to follow up the offspring in 2 r and omized trials of nutrient supplementation during pregnancy to investigate the effect on cardiovascular disease ( CVD ) risk  in offspring . DESIGN We recruited offspring born during 2 trials in The Gambia , West Africa . One trial provided protein-energy-dense food supplements ( 1015 kcal and 22 g protein/d ) to pregnant ( intervention , from 20 wk gestation until delivery ) or lactating ( control , for 20 wk from birth ) women and was r and omized at the village level . The second was a double-blind , individually r and omized , placebo-controlled trial of calcium supplementation ( 1.5 g/d ) , which was also provided from 20 wk gestation until delivery . RESULTS Sixty-two percent ( n = 1267 ) of children ( aged 11 - 17 y ) born during the protein-energy trial were recruited and included in the analysis , and 64 % ( n = 350 ) of children ( aged 5 - 10 y ) born during the calcium trial were recruited and included in the analysis . Fasted plasma glucose was marginally lower in children born to mothers receiving protein-energy supplements during pregnancy than in those children of the lactating group ( adjusted mean difference : -0.05 mmol/L ; 95 % CI : -0.10 , -0.001 mmol/L ) . There were no other differences in CVD risk factors , including blood pressure , body composition , and cholesterol , between children born to intervention and control women from the protein-energy trial . Maternal calcium supplementation during pregnancy was unrelated to offspring blood pressure . CONCLUSION These data suggest that providing supplements to pregnant women in the second half of pregnancy may have little effect on the CVD risk of their offspring , at least in this setting and at the ages studied here . This trial was registered at www.controlled-trials.com as IS RCT N96502494 In a study population that comprised 34 normal black pregnant women , biochemical changes are compared between a group of women who received 1.5 gm of calcium supplementation a day and a group of women who received placebos . The blood pressure-lowering effect of calcium supplementation appears to involve a mechanism that relates parathyroid hormone and plasma renin activity . Other alterations in calcium and magnesium metabolism , as reflected by increased urinary calcium excretion and serum magnesium levels , may also contribute to this effect . Subgroups of study participants with initial ( less than 26 weeks ' gestation ) low levels of serum calcium and plasma renin activity are the ones with the largest reductions in blood pressure . Whether these alterations can produce a reduction in the incidence of pregnancy-induced hypertension is the next question to be answered in this area In an attempt to evaluate the aetiology and therapy of  leg cramps during pregnancy . patients at an antenatal clinic were treated with calcium or a placebo Objective To determine the effect of third-trimester  calcium supplementation on maternal hemodynamic function . Methods Pregnant women were r and omized to receive either 1.5 g of elemental calcium or placebo for 6 weeks during the third trimester . Using Doppler technique , maternal hemodynamic characteristics were measured at baseline , at 2 hours after the first dose of study drug , and at the completion of 6 weeks . Serum , dietary , and urinary calcium levels were also assessed . Power calculation indicated the need to study ten subjects in each group to detect a 1.2 L ( 20 % ) difference in cardiac output between groups , assuming a mean of 6.2 ± 1.0 L/minute . Data were analyzed by analysis of variance for repeated measures , Student t test , Mann-Whitney U test , and Fisher exact test . Results Twenty-three women enrolled , and 18 completed the study . There were no statistically significant differences in demographic characteristics or in serum , dietary , or urinary calcium levels between the two groups . There were also no statistically significant differences in hemodynamic function over time within the calcium supplementation or placebo group ( P > .05 ; analysis of variance for repeated measures ) . After 6 weeks , there were no significant differences between the calcium- and placebo-treated subjects in any hemodynamic measurement . Specifically , there was not a statistically significant difference in cardiac output ( 7.3 ± 1.2 L/minute versus 8.0 ± 0.9 L/minute ; P = .09 ) between the calcium- and placebo-treated groups . Conclusions These findings suggest that third-trimester calcium supplementation does not significantly alter cardiac output . The mechanism by which calcium supplementation lowers blood pressure remains to be eluci date 60 pregnant women underwent a double blind trial with calcium or ascorbic acid ( 1 g twice daily ) as treatment for leg cramps .  There was no significant difference between the two treatment groups with respect to clinical improvement . In 14 out of 60 patients the symptoms were totally abolished and in another 27 patients the symptoms were significantly decreased by the treatment ( irrespective of drug used ) . In 17 patients the symptoms were unaffected while only two patients experienced an increase in frequency of their leg cramps during therapy . Serum total and ionized calcium concentrations , serum total magnesium and albumin concentrations were determined and were not significantly changed throughout therapy in any of the groups . No biochemical differences were found between the different treatment regimens or between those patients relieved or not relieved of their symptoms . Serum magnesium concentrations were at or just below the lower normal limit ( for non pregnant women ) in treated women and pregnant controls
BACKGROUND Maternal nutrition during pregnancy is known to have an effect on fetal growth and development .
It is recommended that women increase their calcium intake during pregnancy and lactation , although the recommended dosage varies among professionals .
Currently , there is no consensus on the role of routine calcium supplementation for pregnant women other than for preventing or treating hypertension .
OBJECTIVES To determine the effect of calcium supplementation on maternal , fetal and neonatal outcomes ( other than for preventing or treating hypertension ) as well as any possible side effects .