VITamin D and OmegA-3 TriaL: Effects on Bone Structure and Architecture (VITAL)

Not Applicable

Completed

Interventions: Dietary Supplement: Vitamin D3 placebo
Dietary Supplement: Vitamin D3
Dietary Supplement: Fish oil placebo
Dietary Supplement: omega-3 fatty acids (fish oil)

Brief Summary: The VITamin D and OmegA-3 TriaL (VITAL; NCT 01169259) is a randomized clinical trial in 25,871 U.S. men and women investigating whether taking daily dietary supplements of vitamin D3 (2000 IU) or fish oil (1 gram of omega-3 fatty acids) reduces the risk of developing cancer, heart disease, and stroke in people who do not have a prior history of these illnesses. This ancillary study is being conducted among a sub-cohort of 771 participants in VITAL and will test the efficacy and safety of high-dose vitamin D supplementation vs. placebo on skeletal health and body composition.

Detailed Description: The VITAL: Effects on Bone Structure and Architecture is an ancillary study of the parent VITAL. This study has enrolled a sub-cohort of 771 VITAL participants at the NIH-sponsored Harvard Catalyst Clinical and Translational Science Center (CTSC). The following measurements will be performed at baseline and 2 years post-randomization to determine whether high-dose vitamin D supplementation vs. placebo: 1) produces small increases or reduces bone loss in spine, hip, and total body areal bone density as assessed by dual x-ray absorptiometry (DXA); 2) reduces bone turnover as assessed by biomarkers of bone resorption and formation; 3) improves (a) volumetric bone mineral density (vBMD) and measures of bone structure as assessed by peripheral quantitative computed tomography (pQCT) and (b) bone microarchitecture as assessed by high resolution pQCT (HR-pQCT) at the distal radius and tibia as well as trabecular bone score (TBS) at the spine; and 4) results in changes in body composition as assessed by DXA. Parallel assessments of the effects of omega-3 fatty acids will be performed. This study may elucidate the mechanisms through which high-dose vitamin D may prevent age-related fractures and provide new insights into the role of vitamin D on skeletal health and body composition.

We are currently analyzing the effects of daily dietary supplements of fish oil (1 gram of omega-3 fatty acids) vs. placebo on skeletal health and body composition.

Recruitment & Eligibility

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Arm && Interventions

Group	Intervention	Description
Vitamin D + fish oil placebo	Vitamin D3	Daily vitamin D (2,000 IU/d) and daily fish oil placebo
Vitamin D placebo + fish oil placebo	Fish oil placebo	Daily vitamin D placebo and daily fish oil placebo
Vitamin D placebo + fish oil placebo	Vitamin D3 placebo	Daily vitamin D placebo and daily fish oil placebo
Vitamin D placebo + fish oil	Vitamin D3 placebo	Daily vitamin D placebo and daily fish oil capsule (1 g/d; EPA + DHA in a 1.2:1 ratio)
Vitamin D + fish oil placebo	Fish oil placebo	Daily vitamin D (2,000 IU/d) and daily fish oil placebo
Vitamin D + fish oil	Vitamin D3	Daily vitamin D (2,000 IU/d) and daily fish oil capsule (1 g/d; EPA + DHA in a 1.2:1 ratio)
Vitamin D placebo + fish oil	omega-3 fatty acids (fish oil)	Daily vitamin D placebo and daily fish oil capsule (1 g/d; EPA + DHA in a 1.2:1 ratio)
Vitamin D + fish oil	omega-3 fatty acids (fish oil)	Daily vitamin D (2,000 IU/d) and daily fish oil capsule (1 g/d; EPA + DHA in a 1.2:1 ratio)

Primary Outcome Measures

Name	Time	Method
Bone Turnover Beta Crosslaps	2 years	To determine whether vitamin D and/or omega-3 supplementation reduces bone turnover, assessed biomarkers of bone resorption (beta crosslaps).
Bone Turnover P1NP	2 years	To determine whether vitamin D and/or omega-3 supplementation reduces bone turnover, assessed biomarkers of bone formation (propeptide of type 1 collagen \[P1NP\]).
Change in Bone Density	2 years	To determine whether vitamin D and/or omega-3 supplementation produces small increases or reduces bone loss in spine, hip, and total body areal bone density, as assessed by DXA. Reported values are rounded up.