Effect of vitamin D supplementation on inflammation: protocol for a systematic review Supplementation with vitamin A early in life and subsequent risk of asthma Randomized trial of vitamin D supplementation for winter-related atopic dermatitis in children.
Introduction The extraskeletal role of vitamin D is being increasingly recognised . This has important clinical implication s , as vitamin D deficiency has reached epidemic proportions worldwide . Vitamin D has proposed anti-inflammatory properties , yet the role of vitamin D supplementation in reducing inflammation remains largely unknown . The purpose of this review is to investigate the impact of vitamin D supplementation on inflammation , and to identify relevant knowledge gaps in the field . Methods and analysis Medline , CINAHL , EMBASE and All EBM will be systematic ally search ed for r and omised controlled trials ( RCTs ) and systematic review s of RCTs , comparing vitamin D supplementation with placebo , usual care or other pharmacological or non-pharmacological interventions . One review er will assess articles for eligibility according to prespecified selection criteria , after which 2 independent review ers will perform data extraction and quality appraisal . Meta-analyses will be conducted where appropriate . Ethics and dissemination Formal ethical approval is not required as no primary data is collected . This systematic review will identify potential clinical implication s of vitamin D deficiency and supplementation , and will be disseminated through a peer- review ed publication and at conference meetings , to inform future research on the efficacy of vitamin D supplementation for inflammation and inflammatory diseases . PROSPERO registration number CRD42016037104 Animal models suggest that vitamin A deficiency affects lung development adversely and promotes airway hyperresponsiveness , and may predispose to an increased risk of asthma .  We examined the long-term effects of vitamin A supplementation early in life on later  asthma risk . In 2006–2008 , we revisited participants from two cohorts in rural Nepal who were enrolled in r and omised trials of vitamin A supplementation . The first cohort received  vitamin A or placebo  for < 16 months during their pre-school years ( 1989–1991 ) . The second cohort was born to mothers who received vitamin A , & bgr;-carotene or placebo before , during and after pregnancy ( 1994–1997 ) . At follow-up , we asked about asthma symptoms and performed spirometry .  Out of 6,421 subjects eligible to participate , 5,430 ( 85 % ) responded to our respiratory survey . Wheezing prevalence during the previous year was 4.8 % in participants aged 9–13 yrs and 6.6 % in participants aged 14–23 yrs . We found no differences between the vitamin A supplemented and placebo groups from either trial in the prevalence of lifetime or current asthma and wheeze or in spirometric indices of obstruction ( p≥0.12 for all comparisons ) . Vitamin A supplementation early in life was not associated with a decreased risk of asthma  in an area with chronic vitamin A deficiency BACKGROUND Epidemiologic and pre clinical data , and a small r and omized trial in Boston , suggest that vitamin D supplementation may improve winter-related atopic dermatitis ( AD ) . OBJECTIVE To determine the effect of vitamin D supplementation on winter-related AD . METHODS We performed a r and omized , double-blind , placebo-controlled trial of Mongolian children with winter-related AD ( clinical trials.gov identifier : NCT00879424 ) . Baseline eligibility included age 2 to 17 years , AD score 10 to 72 using the Eczema Area and Severity Index ( EASI ) , and winter-related AD ( eg , history of AD worsening during the fall-to-winter transition ) . Subjects were enrolled in Ulaanbaatar during winter and r and omly assigned to oral cholecalciferol ( 1000 IU/day ) versus placebo for 1 month . All children and parents received emollient and patient education about AD and basic skin care . The main outcomes were changes in EASI score and in Investigator 's Global Assessment . RESULTS The 107 enrolled children had a mean age of 9 years ( SD 5 ) , and 59 % were male . Their median age of AD onset was 3 months ( interquartile range 2 months to 1 year ) and mean EASI score at baseline 21 ( SD 9 ) . One-month follow-up data were available for 104 ( 97 % ) children . Compared with placebo , vitamin D supplementation for 1 month produced a clinical ly and statistically significant improvement in EASI score ( adjusted mean change : -6.5 vs -3.3 , respectively ; P = .04 ) . Moreover , change in Investigator 's Global Assessment favored vitamin D over placebo ( P = .03 ) . There were no adverse effects in either group . CONCLUSION Vitamin D supplementation improved winter-related AD among Mongolian children , a population likely to have vitamin D deficiency in winter
Conclusions The available very low to low quality evidence does not confirm or rule out beneficial effects of vitamin D supplementation in children with asthma .
Background Epidemiologic studies suggest an association between vitamin D deficiency and atopic diseases , including asthma .
The objective of this study was to systematic ally review the benefits and harms of vitamin D supplementation in children with asthma .