Chow Line: Vitamin D and heart health: jury still out

January 25, 2008

Are vitamin D supplements recommended to prevent heart disease?

It's much too soon for that kind of recommendation, but I think I know where you've gotten that impression. A recent study, published in the American Heart Association's journal Circulation, indicates that low blood levels of vitamin D might be a separate risk factor for heart disease. But -- and this is a big but -- even the researchers who conducted the study aren't recommending vitamin D supplements to prevent heart disease.

Still, the findings of this study were intriguing, especially considering a general concern that Americans 50 and older are at risk of not getting enough vitamin D to maintain bone health. But more on that later.

In this study, researchers examined 1,739 people from the Framingham Heart Study. Their average age was 59 years old, and a bit over half were women. Researchers found that those with the lowest levels of vitamin D in their blood at the beginning of the study had twice the risk of a heart attack, heart failure or stroke over the next five years. When researchers adjusted their findings to control for other risk factors, including high cholesterol, diabetes and high blood pressure, they still found that those with lower levels of vitamin D had a 62 percent higher risk.

Still, scientists are wary of making sweeping recommendations based on these findings. Why? They've been burned before. In the last 10 years or so, similar research indicated other vitamins might play a role in heart health, but those hopes dwindled when the theories were tested under the rigor of large, randomized studies.

At the same time, getting enough vitamin D is important for other reasons. Vitamin D helps the body maintain normal blood levels of calcium and phosphorus, and helps form and maintain strong bones by promoting calcium absorption. Some research suggests that vitamin D may play a role in maintaining a healthy immune system, too.

Luckily, the body can make its own vitamin D when the skin is exposed to ultraviolet rays of sunlight. But the required 10 to 15 minutes of exposure twice a week can be hard to get during the winter. And the older you get, the harder it is for your body to make vitamin D. So, recommendations for vitamin D consumption increase with age, from 200 International Units (IUs) per day up to age 50, to 400 IUs per day from 51 to 70 years, and 600 IUs per day for people 71 and older.

Good sources of vitamin D include fortified milk and yogurt (although other dairy products, such as cheese or ice cream, usually are not good sources); fatty fish, including salmon, mackerel, sardines and tuna fish canned in oil; and breakfast cereals fortified with vitamin D.

Chow Line is a service of Ohio State University Extension and the Ohio Agricultural Research and Development Center. Send questions to Chow Line, c/o Martha Filipic, 2021 Coffey Road, Columbus, OH, 43210-1044, or filipic.3@cfaes.osu.edu.

Editor: February is American Heart Month.

This column was reviewed by Anne Smith, associate professor in the Department of Human Nutrition and director of the Didactic Program in Dietetics in the College of Education and Human Ecology.

 

Author(s): 
Martha Filipic
Source(s): 
Anne Smith