Sunlight, Supplementation Prevent Vitamin D Deficiency

As winter approaches and cooler weather replaces summer’s sunny days, your chance of becoming vitamin D deficient is likely to increase, experts warn – especially if you live in the northern United States and tend to spend a lot of time indoors.

This is because the body will only manufacture vitamin D after the skin has been exposed to sunlight. According to the National Institutes of Health, just 10 to 15 minutes of sunshine three times per week is enough to produce the body’s requirement of vitamin D. Vitamin D, also known as the “sunshine vitamin,” is a fat-soluble vitamin that promotes the body’s absorption of calcium, and is essential for normal development and the maintenance of healthy teeth and strong bones.

But in winter months, when sunlight exposure is minimal, you may need to get your D vitamins from a source other than the sun, such as egg yolks, butter, fatty fish, fortified dairy products, grains – or a high-quality multivitamin or vitamin D supplement.

While the vitamin’s current recommended daily intake is 200 IU for those ages 19 to 50, 400 IU for those ages 51 to 69 and 600 IU for those older than 70; research supports the growing consensus that we need to consume a lot more – up to 1,000 IU – to keep blood levels of vitamin D where they need to be.

And most Americans, experts say, just aren’t where they need to be. Eighty percent of people living in the United States don’t get enough vitamin D, and some individuals are at an especially high risk of deficiency, including: older Americans (because aging skin loses the ability to convert vitamin D to an active form), homebound individuals, people in northern latitudes, people who cover their bodies for religions reasons and those whose occupations prevent them from getting sun exposure.

Other studies indicate that vitamin D may do more for the body than just promote healthy bones and teeth. Experts at Northwestern University, Harvard School of Public Health, Harvard Medical School and the Dana-Farber Cancer Institute in Boston suggest that higher levels of vitamin D may lead to a reduced risk of pancreatic cancer, the fourth leading cause of cancer death in the United States.

In surveying more than 120,000 American men and women, researchers found that those who consumed 600 IU or more of vitamin D each day experienced a 41 percent lower risk for pancreatic cancer when compared to those consuming 150 IU or less.

While experts do note that more research is necessary to determine vitamin D’s inverse role in cancer development, this information coincides with studies dating back to the 1940s, when scientists demonstrated a link between geographic latitudes and deaths from cancer. Those who lived in warmer climates with more exposure to sunlight (and therefore higher vitamin D blood levels) had lower death rates from colon, breast and prostate cancers.

Those at a higher risk for vitamin D deficiency should talk to their doctors about individual situations and specific dietary requirements. But regardless of where you live, experts agree that satisfying your body’s need for D may make life a little sunnier.