Sunlight exposure may help prevent periodontal disease

It only takes a few minutes a day

As the days get shorter and colder, it gets harder to spend time in the sun, and that’s probably bad for your teeth. According to an article in the Journal of Periodontology from a researcher at Washington University School of Medicine in St. Louis, our teeth may be light-sensitive, at least indirectly.

Sunlight allows the body to produce vitamin D, which is good for teeth and bones.
Sunlight allows the body to produce vitamin D, which is good for teeth and bones.

“Calcium and vitamin D are important to oral health,” says Charles F. Hildebolt, D.D.S., Ph.D., associate professor of radiology at Washington University’s Mallinckrodt Institute of Radiology and author of the paper. “The best way to get calcium is through the diet, but we need vitamin D to regulate calcium, and it’s hard to eat enough foods rich in vitamin D to meet that need. The best source of vitamin D is sunshine.”

Vitamin D is important in regulating absorption of calcium in the body. Even if people took in adequate calcium, the body still needs vitamin D to maintain proper calcium levels, both in the bones and in the bloodstream.

“If our systems can’t maintain calcium at particular levels, then the calcium in our bones can be resorbed to maintain serum calcium levels,” Hildebolt says. “That causes problems. We know that 21 percent of Caucasian women over age 50 have osteoporosis and 38 percent have osteopenia, which is a milder form of bone weakening. Half of all Caucasian women over the age of 50 will suffer an osteoporotic fracture at some point before they die.”

These women also will be at risk for periodontal disease, as will men who don’t get enough calcium and vitamin D. That’s because in addition to its role in regulating calcium, vitamin D also has a role in regulating inflammation. In the face of low vitamin D levels, cells produce more cytokines — proteins that contribute to inflammation.

“Periodontal disease is an inflammatory process in which cytokine levels are increased,” he says. “You can actually think of the disease as an overreaction to bacteria in the mouth that causes damage to the bone and the soft tissues that support the teeth.”

A way to lower that risk, he says, is to boost vitamin D levels, and the best way to do that is to increase sun exposure. Hildebolt doesn’t advocate sunbathing or spending time in a tanning bed. He says it takes just a few minutes of exposure on the hands, arms, face and neck to boost vitamin D to the necessary levels. In most parts of the country, about 10 to 15 minutes a couple of times a week is sufficient to provide the body with adequate stores of vitamin D.

Charles Hildebolt
Charles Hildebolt

“A limited amount of sunshine is good,” Hildebolt says. “It’s like many other things. Food is good, but too much of it is harmful. Too much sunshine isn’t good either. But sunshine remains the best way for our bodies to make vitamin D, so we need to get enough sunshine to generate the vitamin D that our systems require.”

The problem is that older people have the highest risk, and many get little or no sunshine, especially during the cold, dark winter months. Even those who get outside tend to wear hats, coats and gloves to keep the skin covered. Plus, winter sunlight isn’t as effective at manufacturing vitamin D in the body as the “warmer” sunlight of spring, summer and fall, which delivers more ultraviolet radiation that the body uses to manufacture vitamin D.

“During the wintertime in a city like Boston, one needs more than five hours of exposure to sunshine to generate any vitamin D at all,” he says. “That makes it hard to get adequate vitamin D from sunshine.”

Because some vitamin D can be stored in body fat, Hildebolt says it is possible to “save up” some sun exposure “for a rainy day.” But it’s unlikely that a person would store up enough vitamin D to make it through the winter without supplementation.

Getting enough sun exposure in the winter months may get slightly easier soon when Daylight Savings Time is extended in much of the country, but Hildebolt says it still will be necessary for people over 50 to take vitamin D supplements during the winter months. He says many calcium pills also contain vitamin D, making those supplements a good way to maintain levels of both key substances.

And he says maintaining adequate calcium and vitamin D has benefits beyond a beautiful smile. Calcium and vitamin D not only lower risk of periodontal disease, but they help keep bones strong and may lower the risk for rheumatoid arthritis, cardiovascular disease and diabetes. Spending some time in the sun seems to be an important part of lowering those risks.

Hildebolt CF. Effect of vitamin D and calcium on periodontitis. Journal of Periodontology, vol. 76(9); pp. 1444-1455, Sept. 2005.

Washington University School of Medicine’s full-time and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children’s hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked third in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children’s hospitals, the School of Medicine is linked to BJC HealthCare.