Predictors of serum 25(Oh)D increase following bimonthly supplementation with 100,000 IU vitamin D in healthy, men aged 25-65 years

Sigal Tepper, Danit R. Shahar, Diklah Geva, Sofia Ish-Shalom

Research output: Contribution to journalReview articlepeer-review

13 Scopus citations


Vitamin D replenishment therapy typically entails standard dosages, but related increases in serum 25(OH)D levels vary between individuals. This study was aimed to identify factors that affect the efficacy of vitamin D supplementation. Subjects and methods 79 healthy men aged 25-65 with 25(OH)D < 20 ng/ml participated in a vitamin D supplementation study. All participants received 100,000 IU vitamin D bimonthly, e.g., 1666 IU/day. Personal and demographic information, physical activity and sun-exposure questionnaires were completed by the participants. Weight, height, and waist circumference were recorded. Serum calcium, creatinine, 25(OH)D, PTH, lipid profile, and liver-enzyme levels were assessed. All measurements were repeated after 6 and 12 months. The difference between baseline serum 25(OH)D and 12-month measurements was calculated (delta). Linear regression was performed to identify predictors for increases in 25(OH)D levels. Results Mean serum 25(OH)D level increases according to BMI were 12.6 ± 5.29 ng/ml for BMI ≠25, 10.12 ± 4.95 ng/ml for 25 < BMI 30, and only 6.39 ;plusmn 5.33 ng/ml for BMI 30, which differed significantly from the other BMI categories (p = 0.003). In a regression model to predict 25(OH)D increase, BMI was the main predictor (p ;< 0.001), explaining 21.6% of the variance in serum 25(OH)D (inverse association). Age, sun-exposure, serum cholesterol, physical-activity, baseline 25(OH)D levels and seasonality were insignificant. The full model explained 27.9% of the variance in serum 25(OH)D. Conclusion This study's main findings are that BMI affect vitamin D response in healthy men. Quantitative supplementation adjustments may be warranted in obese men, for whom the dose may need to be doubled. This article is part of a special issue entitled '16th Vitamin D Workshop'.

Original languageEnglish
Pages (from-to)163-166
Number of pages4
JournalJournal of Steroid Biochemistry and Molecular Biology
Issue numberPART A
StatePublished - 1 Jan 2014


  • 25(OH)D
  • Age
  • BMI
  • Men
  • Season
  • Sun-exposure
  • Supplementation
  • Vitamin D

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Biochemistry
  • Molecular Medicine
  • Molecular Biology
  • Endocrinology
  • Clinical Biochemistry
  • Cell Biology


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