Vitamin D3 or omega-3 supplementation of no help in frailty prevention in older adults

Supplementation with either vitamin D3 or omega-3 fatty acid falls short of reducing the risk of frailty in older adults as compared with placebo, as shown in the ancillary study of the Vitamin D and Omega-3 (VITAL) trial.

VITAL included 25,871 men aged ≥50 years and women aged ≥55 years who were recruited across all 50 states in the US. None of them had cancer or cardiovascular disease. These participants were randomized to receive vitamin D3 (2,000 IU/d), marine omega-3 fatty acids (1 g/d), or placebo.

Researchers measured frailty using a validated 36-item frailty index that included measures of function, cognition, mood, and comorbidities from annual questionnaires. They calculated the change in frailty score from baseline through year 5 based on repeated measures and using an intention-to-treat protocol.

Of the participants enrolled, 25,057 had sufficient data to calculate a frailty index. Their mean age at baseline was 67.2 years, and half (50.7 percent) were women. The mean frailty score was 0.109, and 3,174 participants (12.7 percent) were considered frail.

Over a median follow-up of 5 years, mean frailty scores rose to 0.121. Neither vitamin D3 nor omega-3 fatty acid supplementation exerted favourable effects on mean frailty scores over time (vitamin D3: mean difference −0.0002, p=0.85; omega-3 fatty acid: mean difference −0.0001, p=0.90) or slowed the rate of change in mean frailty score (vitamin D3: p=0.98 for interaction with time; omega-3 fatty acid: p=0.13 for interaction with time).

The incidence of frailty remained similar over time (vitamin D3: p=0.90 for interaction with time; omega-3 fatty acid: p=0.32 for interaction with time). Results were consistent in an analysis that used the frailty physical phenotype.