Baseline characteristics of participants in the VITamin D and OmegA-3 TriaL (VITAL): Effects on Bone Structure and Architecture

Contemp Clin Trials. 2018 Apr;67:56-67. doi: 10.1016/j.cct.2018.02.003. Epub 2018 Feb 23.


Vitamin D supplements are often used to benefit skeletal health, although data on effects of daily high-dose vitamin D alone on bone density and structure are lacking. The ongoing VITamin D and OmegA-3 TriaL (VITAL) is a double-blind, randomized, placebo-controlled trial testing effects of high-dose supplemental vitamin D3 (cholecalciferol; 2000 IU/day) and/or omega-3 fatty acids (FAs; 1 g/day) for the primary prevention of cancer and cardiovascular disease. The study has a mean treatment period of 5 years among 25,874 U.S. men ≥50 years and women ≥55 years old from all 50 states. The ancillary study, VITAL: Effects on Bone Structure and Architecture, is testing effects of vitamin D3 and/or omega-3 FAs on musculoskeletal outcomes and body composition in a subcohort of 771 participants. At in-person visits at the Harvard Catalyst Clinical and Translational Science Center (CTSC), participants completed bone density/architecture, body composition, and physical performance assessments at baseline and two-year follow-up. Baseline characteristics were evenly distributed among treatment groups, suggesting that any uninvestigated confounders will be evenly distributed; sex differences were also analyzed. Future analyses of the two-year follow-up visits will elucidate whether daily high-dose, supplemental vitamin D3 and/or omega-3 FAs improve musculoskeletal outcomes, helping to advance clinical and public health recommendations.

Clinical trial registration number: NCT01747447.

Keywords: Body composition; Bone mineral density; Omega-3 fatty acids; Physical performance; Sex differences; Vitamin D.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Absorptiometry, Photon / methods
  • Biological Availability
  • Body Composition / drug effects*
  • Bone Density / drug effects*
  • Cardiovascular Diseases / prevention & control*
  • Dietary Supplements
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Fatty Acids, Omega-3* / administration & dosage
  • Fatty Acids, Omega-3* / pharmacokinetics
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neoplasms / prevention & control*
  • Physical Functional Performance
  • Primary Prevention
  • Sex Factors
  • Vitamin D* / administration & dosage
  • Vitamin D* / pharmacokinetics
  • Vitamins / administration & dosage
  • Vitamins / pharmacokinetics


  • Fatty Acids, Omega-3
  • Vitamins
  • Vitamin D

Associated data