In adults aged ≥50 years, supplementation with vitamin D did not result in a lower incidence of invasive cancer or cardiovascular (CV) events then placebo, a new study found. Researchers conducted a nationwide, randomized, placebo-controlled trial of vitamin D₃ at a dose of 2000 IU per day and marine n-3 (omega-3) fatty acids at a dose of 1 g per day for the prevention of cancer and CVD among men aged ≥50 years and women aged ≥55 years in the US. Primary end points were invasive cancer of any type and major CV events. Among the findings:

• 25,871 participants (5,106 black), underwent randomization.
• Supplementation with vitamin D was not associated with a lower risk of either the primary end points.
• During a median follow-up of 5.3 years, cancer was diagnosed in 1,617 participants (793 in the vitamin D group and 824 in the placebo group; HR, 0.96).
• A major CV event occurred in 805 participants (396 in the vitamin D group vs 409 in the placebo group; HR, 0.97).