A new study has further highlighted the importance of the Vitamin D group of substances to human health. It appears that Vitamin D deficiency is linked to a higher risk of death. The research was published Monday in the Archives of Internal Medicine, a publication of the Journal of the American Medical Association (JAMA).

Vitamin D is actually a generic name for a group of prohormones (precursors to hormones). Of interest are especially vitamin D2 (or ergocalciferol) and vitamin D3 (or cholecalciferol). The latter is the actual "sunshine vitamin" which is produced in skin exposed to sunlight, specifically ultraviolet B radiation. Vitamin D is found in many dietary sources such as fish, eggs, fortified milk, and cod liver oil.

For the new study, Harald Dobnig an internist and endocrinologist at the Medical University of Graz, Austria, and colleagues studied more than 3,200 people with an average age of 62 who were scheduled for angiography (a heart examination) between 1997 and 2000.

After about eight years of follow-up, the researchers found that 737 patients had died, 463 of them from cardiovascular disease. Some of these people had very low levels of vitamin D in their body, the researchers further discovered when looking at the cause of their death. More exactly, there were 307 deaths in patients with the lowest levels, versus 103 deaths in those with the highest levels.

Even when considering factors like age or physical activity, the study found that deaths from all causes were about twice as common in patients in the lowest-level group.

Earlier this month, Edward Giovannucci, M.D., Sc.D., of Harvard School of Public Health and Brigham and Women’s Hospital, Boston and his colleagues have conducted a study about the link between the low levels of vitamin D and the myocardial infarct. They found out that men with a vitamin D deficiency (having 15 nanograms per milliliter of blood or less) had an increased risk for heart attack compared with those with a sufficient amount (having 30 nanograms per milliliter of blood or more) of vitamin D.