An article in the British Medical Journal looked at whether vitamin D supplementation altered the incidence of major cardiovascular disease. The five-year, randomized, double-blind, placebo-controlled trial included more than 21,000 subjects ages 60 to 84 who were given either 60,000 IU of vitamin D orally per month, or placebo.

The rate of major cardiovascular events was 9 percent lower in the vitamin D group than in the placebo group. The rate was lower in particular among cardiovascular patients who experienced a 19 percent lower rate of heart attack and 11 percent lower rate of coronary artery bypass surgery compared to those not taking vitamin D. There was no difference in stroke rates.

Vitamin D is a very safe supplement as long as proper dosing is practiced. If you are going to supplement with vitamin D, make sure you use natural vitamin D3 not vitamin D2 — the prescription form of vitamin D is often D2.

Most of my patients take approximately 5,000 IU of vitamin D per day, especially during winter.