Multivariable-Adjusted Mean or Geometric Mean Vitamin D–Related Biomarker Concentrations at Baseline, by BMI
WEST, TYPE 2 DIABETES
Abbreviations: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); 25-OHD, 25-hydroxyvitamin D; PTH, parathyroid hormone; VDBP, vitamin D binding protein.SI conversion: To convert albumin to grams per liter, multiply by 10; calcium to millimoles per liter, multiply by 0.25; 25-OHD to nanomoles per liter, multiply by 2.496; PTH to nanograms per liter, multiply by 1.Values were adjusted for baseline factors: age (continuous), sex (male, female), prevalence of type 2 diabetes, preintervention vitamin D supplement use, smoking status (never, past, current, not reported), total physical activity (above, below median = 16.6 MET-h/wk), race and ethnicity (Asian or Pacific Islander, Black, Native American or Alaska Native, non-Black Hispanic, non-Hispanic White, other/unknown, not reported), geographic region (West, South, Midwest, Northeast), season of blood draw (winter, spring, summer, fall), and in-person Clinical and Translational Science Center subgroup participation.Among the 2742 participants with repeated blood collections at year 2, there was a significant mean (SD) 11.9 (8.6) ng/mL increase in serum 25-OHD level in the group randomized to vitamin D supplementation, compared with little change in the placebo group (−0.7 [7.9] ng/mL). Waterfall plots (eFigure in 