Vitamin D and Omega-3 Trial

Vitamin D and Omega-3 Trial (VITAL) (VITamin D and OmegA-3 TriaL) is a 5 year trial to run from 2010 to determine the benefits of vitamin D and Omega-3 supplements on elderly Americans.

It aims to enroll 20,000 participants (women 55 or over, men 50 or over) who will be randomized to one of four groups:
 * daily vitamin D (2000 IU) and fish oil (1 g);
 * daily vitamin D and fish-oil placebo;
 * daily vitamin-D placebo and fish oil;
 * daily vitamin-D placebo and fish-oil placebo.

Participants will answer annual questionnaires to determine effects on risk of cancer, heart disease, stroke, osteoporosis, diabetes, memory loss and depression.