Cited by 331Vitamin D Research StudiesHormonal and reproductive studiesSperm and Testicular Function

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Effect of Vitamin D Supplementation on Testosterone Levels in Men

Open access
Pilz, S., Frisch, S., Koertke, H., Kuhn, J., Dreier, J., Obermayer-Pietsch, B., Wehr, E., Zittermann, A.·2011·Hormone and Metabolic Research

Abstract

The male reproductive tract has been identified as a target tissue for vitamin D, and previous data suggest an association of 25-hydroxyvitamin D [25(OH)D] with testosterone levels in men. We therefore aimed to evaluate whether vitamin D supplementation influences testosterone levels in men. Healthy overweight men undergoing a weight reduction program who participated in a randomized controlled trial were analyzed for testosterone levels. The entire study included 200 nondiabetic subjects, of whom 165 participants (54 men) completed the trial. Participants received either 83 μg (3,332 IU) vitamin D daily for 1 year (n = 31) or placebo (n =2 3). Initial 25(OH)D concentrations were in the deficiency range (< 50 nmol/l) and testosterone values were at the lower end of the reference range (9.09-55.28 nmol/l for males aged 20-49 years) in both groups. Mean circulating 25(OH)D concentrations increased significantly by 53.5 nmol/l in the vitamin D group, but remained almost constant in the placebo group. Compared to baseline values, a significant increase in total testosterone levels (from 10.7 ± 3.9 nmol/l to 13.4 ± 4.7 nmol/l; p < 0.001), bioactive testosterone (from 5.21 ± 1.87 nmol/l to 6.25 ± 2.01 nmol/l; p = 0.001), and free testosterone levels (from 0.222 ± 0.080 nmol/l to 0.267 ± 0.087 nmol/l; p = 0.001) were observed in the vitamin D supplemented group. By contrast, there was no significant change in any testosterone measure in the placebo group. Our results suggest that vitamin D supplementation might increase testosterone levels. Further randomized controlled trials are warranted to confirm this hypothesis.

Overview

AI snapshot

Written from the paper’s full text.

TL;DR

In a subgroup analysis of overweight men from a 1-year randomized vitamin D trial, daily 83 µg vitamin D increased all measured testosterone fractions, whereas placebo did not. The authors conclude vitamin D supplementation might increase testosterone, but confirmatory randomized controlled trials are needed.

Key findings

  • In the vitamin D group (n=31), total testosterone increased from 10.7 ± 3.9 to 13.4 ± 4.7 nmol/l (p<0.001), bioactive testosterone from 5.21 ± 1.87 to 6.25 ± 2.01 nmol/l (p=0.001), and free testosterone from 0.222 ± 0.080 to 0.267 ± 0.087 nmol/l (p=0.001).
  • In the placebo group (n=23), no significant change was found in total testosterone (11.8 ± 4.0 vs. 12.7 ± 5.45 nmol/l, p=0.355), bioactive testosterone (6.39 ± 2.22 vs. 6.59 ± 2.33 nmol/l, p=0.626), or free testosterone (0.264 ± 0.087 vs. 0.278 ± 0.097 nmol/l, p=0.532).
  • Circulating 25(OH)D increased by 53.5 ± 65.3 nmol/l to 86.4 ± 68.8 nmol/l in the vitamin D group (p<0.001), but increased only nonsignificantly in the placebo group (by 5.8 ± 21.3 nmol/l to 35.5 ± 18.0 nmol/l; p=0.215).
  • In the placebo group, men recruited in the winter half-year had nonsignificantly lower 25(OH)D, total testosterone, bioactive testosterone, and free testosterone than men recruited in the summer half-year.

Methods

  • Subgroup analysis of a previously published prospective, double-blind randomized controlled trial in nondiabetic overweight subjects undergoing a 12-month weight reduction program; 200 subjects were included (62 men), and 165 completed (54 men analyzed: 31 vitamin D, 23 placebo).
  • Participants received either 83 µg (3 332 IU) vitamin D daily or placebo for 1 year; fasting blood samples were drawn at baseline and after 1 year, with 25(OH)D measured by radioimmunoassay, testosterone and SHBG by Immulite 2000, and bioactive/free testosterone calculated according to Vermeulen et al.
  • Baseline characteristics are presented as means ± SD; intra-group paired t-tests were used rather than intergroup comparisons because no sex-stratified randomization was performed at baseline; p<0.05 was considered statistically significant.

Limitations

  • The paper states that the effect of vitamin D supplementation on testosterone was not a prespecified study outcome, that testosterone-related functions such as libido, mood, or muscle strength were not assessed, that the number of male participants was relatively small, and that future studies must clarify whether vitamin D actions are mediated by a pituitary or testicular effect.
  • Evident from the text: this is a subgroup analysis of male participants from a trial not sex-stratified at baseline, and the main testosterone comparisons were within-group rather than between-group, limiting causal inference.

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Integrity signals

Registry

Crossref · 10.1055/s-0030-1269854

Cites

Statistics

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Verification

Claims the paper makes

10 Own result · 8 Sources not found · 8 Own method · 2 Own interpretation

Show all 13 claims

  • Probably not a substantial claim. 15
  • It may state two separate claims as one. 3
  • The quote only partly states this claim. 1
15 of 15
  • The authors state this as an assumption.

    Whether there exists a causal link between vitamin D and testosterone status is currently not known.

    “Whether there exists a causal link between vitamin D and testosterone status is, however, currently not known.”
  • The authors state this as an assumption.

    This work is the first study specifically addressing the effect of vitamin D supplementation on androgens in men.

    “This work is, to the best of our knowledge, the fi rst study, which specifi cally addresses the eff ect of vitamin D supplementation on androgens in men.”
  • The authors state this as an assumption.

    The similar decrease in PTH and the similar trend for an increase in 1,25(OH)2D in both study groups is due to a nonlinear association of these 2 calciotropic hormones with increasing circulating 25(OH)D levels, with a pronounced effect at low and virtually no effect at high 25(OH)D levels.

    “We assume that the similar decrease in PTH and the similar trend for an increase in 1,25(OH) 2 D in both study groups is due to a nonlinear association of these 2 calciotropic hormones with increasing circulating 25(OH)D levels [10] , with a pronounced eff ect at low and virtually no eff ect at high 25(OH)D levels.”
3 of 3

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Citations

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Research works printed but not linked: 10

  1. Holick MF . N Engl J Med 2007 ; 357 : 266 -281
  2. Bouillon R , Carmeliet G , Verlinden L , van Etten E , Verstuyf A , Luderer HF , Lieben L , Mathieu C , Demay M . Endocr Rev 2008 ; 29 : 726 -776
  3. Blomberg Jensen M , Nielsen JE , Jorgensen A , Rajpert-De Meyts E , Kris- tensen DM , Jorgensen A , Skakkebaek NE , Juul A , Leff ers H . Hum Reprod 2010 ; 25 : 1303 -1311
  4. Haring R , V ö lzke H , Steveling A , Krebs A , Felix SB , Sch ö fl C , D ö rr M , Nauck M , Wallaschofski H . Eur Heart J 2010 ; 31 : 1494 -1501
  5. Allan CA , Strauss BJ , Burger HG , Forbes EA , McLachlan RI . J Clin Endo- crinol Metab 2008 ; 93 : 139 -146
  6. Wehr E , Pilz S , Boehm BO , M ä rz W , Obermayer-Pietsch B . Clin Endocri- nol (Oxf) 2010 ; 73 : 243 -248
  7. Zittermann A , Frisch S , Berthold HK , G ö tting C , Kuhn J , Kleesiek K , Stehle P , Koerke H , Koerfer R . Am J Clin Nutr 2009 ; 89 : 1321 -1327
  8. Vermeulen A , Verdnock L , Kaufman JM . J Clin Endocrinol Metab 1999 ; 84 : 3666 -3672
  9. Krasnoff JB , Basaria S , Pencina MJ , Jasuja GK , Vasan RS , Ulloor J , Zhang A , Coviello A , Kelly-Hayes M , D ' Agostino RB , Wolf PA , Bhasin S , Mura- bito JM . J Clin Endocrinol Metab 2010 ; 95 : 2790 -2799 10
  10. Zittermann A . Prog Biophys Mol Biol 2006 ; 92 : 39 -48

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Metadata

Authors
Pilz, S., Frisch, S., Koertke, H., Kuhn, J., Dreier, J., Obermayer-Pietsch, B., Wehr, E., & Zittermann, A.
Affiliations
  • Medical University of Graz (AT)
  • Heart and Diabetes Center North Rhine-Westphalia (DE)
Venue
Hormone and Metabolic Research
Published
2010-12-10
Volume
43
Issue
03
Pages
223-225
ISSN
  • 0018-5043 (ISSN-L)
  • 1439-4286
OpenAlex
W2079831502
Cited by
325
References
0
Citations by year
2026: 8 · 2025: 14 · 2024: 21 · 2023: 15 · 2022: 18 · 2021: 27 · 2020: 74 · 2019: 22 · 2018: 17 · 2017: 23 · 2016: 19 · 2015: 15 · 2014: 21 · 2013: 13 · 2012: 12
FWCI
6.60
Type
journal article
Language
en
Open access
Locations
  • Hormone and Metabolic Research (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Vitamin D Research Studies
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Hormonal and reproductive studies
  • Health Sciences › Medicine › Reproductive Medicine › Sperm and Testicular Function
Keywords
vitamin D supplementation, testosterone, 25-hydroxyvitamin D, free testosterone, male reproductive tract, vitamin D deficiency, weight loss, overweight men
MeSH terms
Adult, Humans, Middle Aged, Obesity, Testosterone, Vitamin D, Dietary Supplements

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