title: Vitamin D supplementation and testosterone concentrations in male human subjects.
abstract: OBJECTIVE
  A possible association between serum 25-hydroxyvitamin D and testosterone levels has been reported; however, contradictory results have emerged.
  
  
  METHODS
  To investigate a causal link between vitamin D and testosterone status, we studied the effect of vitamin D supplementation on serum testosterone concentrations in three independent intervention studies including male patients with heart failure (study 1), male nursing home residents (study 2) and male non-Western immigrants in the Netherlands (study 3).
  
  
  METHODS
  In study 1, 92 subjects were randomized to either vitamin D (2000 IU cholecalciferol daily) or control. Blood was drawn at baseline, after 3 and 6 weeks. In study 2, 49 vitamin D deficient subjects received either vitamin D (600 IU daily) or placebo. Blood was drawn at baseline, after 8 and 16 weeks. In study 3, 43 vitamin D deficient subjects received either vitamin D (1200 IU daily) or placebo. Blood was drawn at baseline, after 8 and 16 weeks. Serum 25-hydroxyvitamin D levels were measured using LC-MS/MS or radioimmunoassay. Testosterone levels were measured using a 2nd generation immunoassay.
  
  
  RESULTS
  Serum 25-hydroxyvitamin D levels significantly increased in all treatment groups (median increase of 27, 30 and 36 nmol/l in studies 1, 2 3, respectively) but not in the control groups. The documented increase in 25-hydroxyvitamin D levels, however, did not affect mean testosterone concentrations at the end of the study (median increase of 0, 0.5 and 0 nmol/l in studies 1, 2 and 3, respectively).
  
  
  CONCLUSIONS
  In this post hoc analysis of three small clinical trials of limited duration in men with normal baseline testosterone concentrations, vitamin D supplementation was not associated with an increase in circulating testosterone concentrations.
authors.affiliation: Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Annemieke C
authors.initials: AC
authors.lastname: Heijboer
authors.affiliation: Department of Internal Medicine, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Mirjam
authors.initials: M
authors.lastname: Oosterwerff
authors.affiliation: Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Nicolas F
authors.initials: NF
authors.lastname: Schroten
authors.affiliation: Department of Internal Medicine, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Elisabeth M W
authors.initials: EM
authors.lastname: Eekhoff
authors.affiliation: Overduin Katwijk, Katwijk, the Netherlands.|Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Victor G M
authors.initials: VG
authors.lastname: Chel
authors.affiliation: Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Rudolf A
authors.initials: RA
authors.lastname: de Boer
authors.affiliation: Department of Clinical Chemistry, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Marinus A
authors.initials: MA
authors.lastname: Blankenstein
authors.affiliation: Department of Internal Medicine, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Paul
authors.initials: P
authors.lastname: Lips
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002762:Cholecalciferol / Q000627:therapeutic use*; D015331:Cohort Studies; D019587:Dietary Supplements; D054242:Emigrants and Immigrants; D006333:Heart Failure / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D009735:Nursing Homes; D013739:Testosterone / Q000097:blood*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000188:drug therapy*; D014815:Vitamins / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D014815:Vitamins; D014807:Vitamin D; D002762:Cholecalciferol; D013739:Testosterone; C104450:25-hydroxyvitamin D