Recent Studies Reveal What’s New Under the Sun

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Here’s a solar paradox: Sunshine is known to cause skin cancer. Yet, because of the benefits of vitamin D, sunlight may actually protect against the lethal effects of other cancers.

In fact, new evidence suggests that the vitamin D may play a role not only in cancer survival but in keeping the heart healthy and the bones strong, ultraviolet rays are the major source of vitamin D in humans

In a recent study scientists from Norway’s Institute for Cancer Research in Oslo and the U.S. Department of Energy’s Brookhaven National Laboratory in Upton, N.Y., found that people who live in sunny Australia produce nearly five times more vitamin D than those who live in far less sunny Scandinavia and more than three times more than people in the United Kingdom.

People in the southern climes were significantly less likely than their northern neighbors to die from colon, lung, breast and prostate cancer, according to a report on the study in the Jan. 7 online edition of Proceedings of the National Academy of Sciences, The researchers concluded that the increased vitamin D levels the higher survival rates resulted from moderately increased exposure to sunlight.

A second study, with more than 1,700 offspring of the original participants in the 50-year-old Framingham Heart Study, found that those with the lowest levels of vitamin D had twice the risk of having a heart attack or stroke in the next five years as those who had higher levels. The risk was especially high for those who had high blood pressure as well as low levels of vitamin D. At the beginning of the study, published Jan. 7 in the journal Circulation, none of the men and women, who averaged age 59, had a history of heart disease.

Vitamin D also may help slow bone loss. Doctors have long prescribed calcium supplements to older women to slow bone loss—but after a while, supplements may not do the job. New research by Australian scientists underscores that adding vitamin D boosts the absorption of calcium.

The study, with 120 women ages 70 to 80, pitted calcium supplements against a placebo and against a combination of calcium and vitamin D. After five years, only the women who took the combination maintained bone density, according to a report on the study in the Jan. 17 online edition of Journal of Clinical Endocrinology and Metabolism.

“It’s certainly true that vitamin D enhances calcium uptake in bones—and it does much more than that,” says Robert P. Heaney, M.D., of Creighton University in Omaha, an expert on calcium and vitamin D. “The body uses vitamin D in virtually every tissue. When we talk about adequate vitamin D, we’re talking about total body health.”

“Most Americans of all ages aren’t getting enough vitamin D,” says Ronald Krauss, M.D., senior scientist at Children’s Hospital Oakland Research Institute.

If you can’t get into the sunshine, Krauss suggests taking supplemental vitamin D3, which is more potent than vitamin D2. “And talk to your doctor about checking your vitamin D level,” he adds. A simple blood test called the 25-hydroxy vitamin D test can determine whether your body has enough, too little or too much vitamin D. Medicare will pay for the test if your doctor prescribes it. If you’re not in Medicare, ask your health plan if it covers the test.

Is it too late for people over 50 to have their day in the sun? “It’s never too late,” says Johan Moan of Norway’s Cancer Research Institute. “In fact, older people need more sun than younger ones.”

Read More: How Much Time Do You Need in the Sun?