First large-scale trial to study effects of Vitamin D and fish oil on disease prevention to begin in 2010

Can taking vitamin D and fish oil supplements help protect us from developing cancer or cardiovascular disease? Boston researchers are preparing to find out with the launch of a large, national trial that will involve approximately 20,000 healthy older people. Of those, 5,000 will be African Americans - a population of people who exhibit higher rates of cancer, heart disease and stroke compared to whites. "African-Americans have a higher risk of vitamin D deficiency and a greater frequency of certain types of cancer and diabetes and hypertension, so I think that it will be of great importance to look at whether something as simple as taking a vitamin D supplement can narrow these health gaps," explains Dr. JoAnn Manson of the Harvard Medical School and Brigham and Women's Hospital. It is believed that the darker skin makes African Americans less able to generate vitamin D from absorbing sunlight.

The study, which will begin early next year and extend over a five-year period, is being funded by the National Institutes of Health. According to Dr. Manson, it is "one the first large-scale randomized trials to target a specific group at higher risk for a deficiency of nutrients." She notes that while such vitamin supplements as vitamin E, C, beta carotene, folic acid and selenium have shown promise in terms of disease prevention, their benefits have never been proven in large-scale trials. Fish oil has been studied in larger trials, but only with people who have had heart attacks or diabetes. 

Participants will be randomly assigned into four groups, with some taking 2,000 international units of vitamin D and approximately 1 gram of fish oil daily. Others will be given pills that have no active ingredients, while two other groups will take a real supplement and one placebo of either vitamin D or fish oil. "What's most exciting is these low-cost supplements have the potential for a tremendous reduction in the burden of chronic disease in this country and throughout the world if they are shown to be effective," says Dr. Manson. "That's what this is all about: to get rigorous high quality information about the balance between the benefits and risks of taking moderate to high doses of these supplements."

News Release: Brigham study will test vitamin D, fish oil supplements   www.boston.com  June 22, 2009