Doctors Say Sunlight-starved New Englanders Are Suffering

WINTER HARBOR — Many millennia ago, when we lived near the equator and walked around naked, no one worried about getting enough vitamin D from the sun.

But that was then and this is now, especially for New Englanders in the winter, say researchers, who add that insufficient vitamin D can have effects ranging from osteoporosis and depression to diabetes and fibromyalgia.

“Vitamin D inadequacy constitutes a largely unrecognized epidemic in many populations worldwide,” said Dr. Michael Holick, professor of medicine at Boston University School of Medicine and a well-known researcher into vitamin D.

He said New England residents are vitamin D deficient year-round, with the greatest depletion evident in the winter months.

Susan Sullivan, who teaches food science and human nutrition at the University of Maine at Orono, said, “we do not make vitamin D in our skin from November to March, so our blood levels drop over the course of the winter.”

Vitamin D is a nutrient naturally produced in skin exposed to the sun’s ultraviolet rays.

It was first added to the milk supply in the 1930s to prevent rickets, a bone-deforming disease. It also is known to be protective against osteoporosis by aiding the absorption of calcium into bone cells.

Sullivan said most people are unaware vitamin D also helps support the immune system and is believed to help prevent certain types of cancer, diabetes, multiple sclerosis, and possibly colds and flu.

In addition to milk, among the best food sources for vitamin D are oily fish such as salmon, mackerel and sardines; cod liver oil; egg yolks; orange juice; some yogurts and margarine.

The average fair-skinned person in the past could get the equivalent of 10,000 IU (international units) by spending 10 to 15 minutes outdoors a few times a week.

But this isn’t as easy as it sounds. Some climates have less sunlight than others and people either don’t spend enough time outdoors or wear sunscreen when they do, which prevents synthesis of vitamin D.

As a result, the American Academy of Pediatrics in October doubled its recommended minimum daily intake of vitamin D for infants, children and teens from 200 IU to 400 IU.

For adults, the government recommends 200 IU of vitamin D each day up to age 50, with an additional 200 IU at 60 and then again at 70.

But many researchers say those levels are much too low and that food sources, such as milk and salmon, do not provide enough vitamin D.

Sullivan, from the University of Maine, said adults living in Maine in the winter should take 1,000 IU of vitamin D daily.

Dr. Benjamin Newman, the “Village Doctor” who recently set up practice in Winter Harbor, said adults should be getting 2,000 IU of vitamin D3 each day and children 1,000 IU.

Holick, professor of medicine at Boston University School of Medicine, recommends a minimum 1,000 IU supplement daily along with a multivitamin containing 400 IU.

Holick said patients don’t have to worry about taking too much vitamin D. Toxicity doesn’t become a problem until you take more than 10,000 IU daily for at least six months.

In a March 2006 review article in the journal Mayo Clinic Proceedings, Holick said vitamin D inadequacy has been reported in about 36 percent of otherwise healthy young adults and up to 57 percent of general medicine inpatients in the United States and in even higher percentages in Europe.

He attributed the decrease in absorption of vitamin D to low sunlight exposure, age-related decreases in synthesizing it through the skin, diets low in vitamin D, obesity, sunscreen use and skin pigmentation.

“When vitamin D levels are low, calcium absorption is insufficient to satisfy the calcium requirements not only for bone health but also for most metabolic functions and neuromuscular activity,” Holick said in the article.

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