Vitamin-D and Stroke Risk in Asians

Picture credit: www.smh.com.au

Low Vitamin D in diet increases stroke risk in Japanese-Americans

• Japanese-American men who did not eat foods rich in vitamin D had higher stroke risk.
• Foods rich in vitamin D are important because synthesizing vitamin D from the sun gets harder as we age.

Japanese-American men who don't eat a diet rich in vitamin D have an increased risk of stroke later in life, according to a new, long-term study.

Vitamin D is an essential nutrient that helps prevent rickets in children and severe bone loss in adults, and researchers believe it has the potential to lower the risk of a host of diseases including cancer and diabetes.

The study included nearly 7,400 Japanese-American men living in Hawaii. They were between the ages of 45 and 68 in the mid- to late-1960s, when they were first examined and interviewed about their eating habits.

Researchers calculated risk while adjusting for age, total calorie intake, body-mass index, hypertension, diabetes, cigarette smoking, physical activity, cholesterol levels  and alcohol intake.

During 34 years of follow-up, 960 of the men suffered strokes. Compared to those with the highest levels of vitamin D in their diet, men who took in the least dietary vitamin D had a 22 percent higher risk of stroke and a 27 percent higher risk of ischemic (blood-clot-related) stroke. No difference existed for hemorrhagic (bleeding) stroke, however.

"Our study confirms that eating foods rich in vitamin D might be beneficial for stroke prevention," study author Dr. Gotaro Kojima, a geriatric medicine fellow at the John A. Burns School of Medicine at the University of Hawaii in Honolulu, said in a journal news release.

Kojima said, however, it's unclear whether the study findings could be applied to women or to different ethnic groups.

Sunlight generally is the primary source of vitamin D, but synthesizing vitamin D from the sun becomes more difficult as people age, Kojima said, meaning older people need to eat more foods rich in vitamin D or take supplements. Fortified milk, breakfast cereals, fatty fish and egg yolks all are good sources of vitamin D.

###

The above story is based on the May 22, 2012 news release the American Heart Association/American Stroke Asociation.

The research was published ahead of print in Stroke, an American Heart Association journal: Kojima G, Bell C, Abbott RD, Launer L, Chen R, Motonaga H, Ross GW, Curb JD, Masaki K. Low Dietary Vitamin D Predicts 34-Year Incident Stroke - The Honolulu Heart Program. Stroke. Published online before print May 24, 2012, doi: 10.1161/​STROKEAHA.112.651752http://stroke.ahajournals.org/content/early/2012/05/24/STROKEAHA.112.651752.abstract

More information

The American Heart Association offers information on Dietand Lifestyle Recommendations. 

The American Stroke Association offers information on Stroke 

The U.S. Office of Dietary Supplements has more about vitamin D.