madman
Super Moderator
Abstract
Purpose It has been hypothesized that vitamin D is associated with androgen levels in men. We, therefore, aimed to evaluate whether vitamin D supplementation increases serum total testosterone (TT) levels in men with low TT levels at baseline.
Methods The Graz Vitamin D&TT-RCT is a single-center, double-blind, randomized placebo-controlled trial conducted between March 2013 and November 2017 at the endocrine outpatient clinic at the Medical University of Graz, Austria. One-hundred healthy men with serum TT levels <10.4 nmol/l and 25-hydroxyvitamin D [25(OH)D] levels<75 nmol/l participated in the trial. Subjects were randomized to receive 20,000 IU of vitamin D3/week (n=50) or placebo (n=50) for 12 weeks. Primary outcome was TT measured using mass spectrometry. Secondary outcomes were free testosterone, free androgen index, sex hormone-binding globulin, estradiol, follicle-stimulating hormone, luteinizing hormone, metabolic characteristics, and body composition.
Results Ninety-four men [mean age and 25(OH)D: 47 (±12) years and 56.3 (±18.3) nmol/l, respectively] completed the study. We found no significant treatment effect on serum TT or on the remaining secondary outcome variables.
Conclusion Vitamin D treatment had no effect on serum TT levels in middle-aged healthy men with low TT levels.
In summary, we found no significant vitamin D effect on androgen levels including TT, FT and FAI concentrations in this cohort of middle-aged healthy men with low baseline serum TT levels. This finding confirms our previous results in men with normal serum TT levels and suggests that vitamin D treatment has no clinical relevant effect on testosterone levels in men. Of note, future studies should only be performed in truly vitamin D-deficient subjects (<25 or 30 nmol/l) and low testosterone levels to evaluate vitamin D effects on testosterone levels.
Purpose It has been hypothesized that vitamin D is associated with androgen levels in men. We, therefore, aimed to evaluate whether vitamin D supplementation increases serum total testosterone (TT) levels in men with low TT levels at baseline.
Methods The Graz Vitamin D&TT-RCT is a single-center, double-blind, randomized placebo-controlled trial conducted between March 2013 and November 2017 at the endocrine outpatient clinic at the Medical University of Graz, Austria. One-hundred healthy men with serum TT levels <10.4 nmol/l and 25-hydroxyvitamin D [25(OH)D] levels<75 nmol/l participated in the trial. Subjects were randomized to receive 20,000 IU of vitamin D3/week (n=50) or placebo (n=50) for 12 weeks. Primary outcome was TT measured using mass spectrometry. Secondary outcomes were free testosterone, free androgen index, sex hormone-binding globulin, estradiol, follicle-stimulating hormone, luteinizing hormone, metabolic characteristics, and body composition.
Results Ninety-four men [mean age and 25(OH)D: 47 (±12) years and 56.3 (±18.3) nmol/l, respectively] completed the study. We found no significant treatment effect on serum TT or on the remaining secondary outcome variables.
Conclusion Vitamin D treatment had no effect on serum TT levels in middle-aged healthy men with low TT levels.
In summary, we found no significant vitamin D effect on androgen levels including TT, FT and FAI concentrations in this cohort of middle-aged healthy men with low baseline serum TT levels. This finding confirms our previous results in men with normal serum TT levels and suggests that vitamin D treatment has no clinical relevant effect on testosterone levels in men. Of note, future studies should only be performed in truly vitamin D-deficient subjects (<25 or 30 nmol/l) and low testosterone levels to evaluate vitamin D effects on testosterone levels.
