16 March 2010
Studies support association of higher vitamin D levels with disease risk reduction
The results of two studies conducted by Intermountain Medical Center Heart Institute in Murray Utah, presented on March 15, 2010 at the American College of Cardiology's 59th annual scientific session in Atlanta, show that individuals who increase their vitamin D levels experience a lower risk of cardiovascular disease, heart attack, heart failure, high blood pressure, diabetes, depression, kidney failure and all-cause mortality over a given period of time.
The first study included 9,491 participants in whom low vitamin D levels of 30 nanograms per milliliter (considered "normal" by some practitioners) or less were detected. Nearly 80 percent of the subjects were women. Among the 47 percent who increased their vitamin D levels to 30 nanograms per milliliter or more between their initial and follow-up examinations, there was a decrease in the risk of coronary artery disease, heart failure, renal failure and death compared with those whose vitamin D levels failed to reach this level.
In the second study, the disease-predictive value of varying levels of vitamin D in 31,289 subjects aged 50 and older was analyzed. The researchers concluded that having a vitamin D level of greater than 43 nanograms per milliliter was optimal to significantly lower the risk of seven out of ten outcomes during the period examined: death, diabetes, coronary artery disease, myocardial infarction, heart failure, depression and renal failure.
"It was very important to discover that the 'normal' levels are too low," noted research team member Dr Heidi T. May. "Giving physicians a higher level to look for gives them one more tool in identifying patients at-risk and offering them better treatment."
"Vitamin D replacement therapy has long been associated with reducing the risk of fractures and diseases of the bone," noted Joseph Brent Muhlestein, MD, who is the director of cardiovascular research at the Intermountain Medical Center Heart Institute and co-researcher in both studies. "But our findings show that vitamin D could have far greater implications in the treatment and reduction of cardiovascular disease and other chronic conditions than we previously thought."
Dr Muhlestein remarked that increasing vitamin D intake by supplementing with 1,000 to 5,000 international units per day may be appropriate for some people.
"Although randomized trials would be useful and are coming, I feel there is enough information here for me to start treatment based on these findings," he added.