DO-HEALTH

Design

DO-HEALTH was a 3-year, 2×2×2 factorial RCT in 2,157 community-dwelling adults aged >=70 across five European countries. Participants were randomised to:

• vitamin D₃ 2,000 IU/day or placebo;
• 1 g/day marine omega-3 or placebo;
• a structured home-exercise programme or a control programme.

Primary endpoints included a composite of six clinically meaningful outcomes: change in systolic and diastolic blood pressure, physical function (Short Physical Performance Battery), cognitive function (MoCA), and incidence of non-vertebral fractures and infections.

Findings

The primary composite endpoint was not improved by any single intervention or their combination. Smaller signals appeared for some secondary endpoints, but the headline result was a clear negative for vitamin D and omega-3 supplementation as healthspan interventions in generally healthy, vitamin-D-replete older adults.

Why it matters

DO-HEALTH is one of the largest and best-conducted trials of widely recommended supplements in older adults. Its negative result has substantially tempered enthusiasm for routine vitamin D and omega-3 supplementation for general aging prevention, while leaving room for benefit in deficient populations or for specific endpoints.

Limitations

Trial population was relatively healthy and well-nourished; results may not generalise to deficient or frail populations. Three years is short relative to cumulative effects of long-term supplementation.

Related entries

See also: Mediterranean diet, Exercise.