Researchers from Johns Hopkins University have found that low levels of vitamin D doubles the risk of stroke among white people, but not blacks. According to the Centers for Disease Control and Prevention, nearly 137,000 Americans die from stroke each year.

The scientists noted that their recent findings further demonstrate the association between vitamin D deficiency and higher rates of death, peripheral artery disease and heart disease in adults, in which they found through previous research.

More than 8,000 healthy men and women of both races were examined, as the researchers compared the risk of death from stroke and vitamin D levels. Among the participants, 6.6 percent of whites were severely vitamin D deficient while compared to 32.3 percent of blacks. According to the investigators, blacks are more likely to have low vitamin D levels due to their dark skin.

After a 14-year follow-up, 176 of the subjects had died from stroke and the researchers noted that 116 were white while 60 were black.

The researchers recommend that people can eat salmon, tuna, or fortified dairy products to maintain good vitamin D levels.