Vitamin D linked to lower heart disease risk

Vitamin D linked to lower heart disease risk - latimes.com: "Raising the amount of vitamin D in the blood appears to help some people -- at least those deficient in the vitamin -- reduce their risk of heart disease by about 30%, researchers announced Monday. The findings, though preliminary, support further investigation of the interplay between vitamin D and heart health.
Observational studies have linked heart disease with low vitamin D levels in the blood. In recent years, studies have shown that as many as three-quarters of Americans have a concentration in their blood that is under the normal level of 30 nanograms per milliliter.

But it has been unclear if people with low vitamin D have more heart disease because of the vitamin deficiency or for other reasons, such as lack of exercise".