Effects of vitamin D supplementation during weight loss on sex hormones in postmenopausal women.

ABSTRACT: The aim of the study was to compare the effects of vitamin D3 supplementation versus placebo on serum sex hormones in postmenopausal women completing a 12-month diet + exercise weight loss program.Two hundred eighteen overweight or obese women (50-75 y) with serum 25-hydroxyvitamin D at least 10 to less than 32?ng/mL ("insufficient") were randomized to either weight loss + 2,000?IU/day oral vitamin D3, or to weight loss + daily placebo. Serum sex hormone-binding globulin, estrone, total, free, and bioavailable estradiol, and testosterone were measured by radioimmunoassay before randomization and at 12 months. Mean changes were compared between groups (intent-to-treat) using generalized estimating equations.The 12-month changes in sex hormone-binding globulin, estrone, total, free, and bioavailable estradiol, and testosterone did not differ between groups (all P?>?0.05). However, a greater increase in serum 25-hydroxyvitamin D was associated with a greater increase in sex hormone-binding globulin (Ptrend?=?0.01), and larger decreases in free and bioavailable estradiol (Ptrend?=?0.04, Ptrend?=?0.03, respectively). In post-hoc analyses, we compared women randomized to vitamin D whose serum 25-hydroxyvitamin D remained insufficient (n?=?38), to women who became replete (25-hydroxyvitamin D ?32?ng/mL; n?=?53). Replete women showed greater reductions in bioavailable estradiol (-1.8 vs -0.7?pg/mL), free testosterone (-0.8 vs -0.3?pg/mL), and bioavailable testosterone (-1.8 vs -0.6?ng/dL), and a greater increase in sex hormone-binding globulin (10.6 vs 4.7?nmol/L) (all P?

SUBMITTER: Mason C 

PROVIDER: S-EPMC4874908 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature