A new long-term study by University of Hawaii medical school researchers shows that Japanese-American men who do not eat a diet rich in vitamin D have an increased risk of stroke later in life.

The study, which appeared May 24 in the journal Stroke, began in the 1960s and followed nearly 7,400 Japanese-American men living in Hawaii who were between the ages of 45 and 68 at the time. 

US News reports:

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.

… 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.

It’s unclear if the study’s findings can be applied to women or to different ethnic groups. Read the full story.