Dr. Robert Heaney, professor of internal medicine at St. Louis University School of Medicine, says 40 percent of his patients get too little vitamin D. He fears the condition could result in health problems as people age.
That corresponds with the 40 percent of Americans and more than 500 million worldwide who get too little vitamin D to stay healthy, according to the World Health Organization.
Vitamin D is known as the “sunshine vitamin” because people normally would get most of what they need from exposing their skin to the sun. UVB rays turn cholesterol in the skin into vitamin D.
And that’s the snag. As scientists find that vitamin D helps conditions from bones to heart health, physicians are rethinking the guidelines for sun exposure — to the chagrin of doctors who believe that’s an invitation to more skin cancer.
Fish oils, fish and fortified dairy products are the main vitamin D sources in food. “But you can eat fish every day of the week and be deficient in vitamin D,” Heaney says. “Vitamin D is difficult to get from food.”
Indeed, the American Vitamin D Council cites research that 10 to 15 minutes in the sun makes up to 12,000 IU (international units) of vitamin D. A sunburn can make up to 50,000. A multivitamin may have 400 IU, which is the recommended daily amount of vitamin D for adults, according to the National Institutes of Health.
Dr. John Cannell, founder of the American Vitamin D Council, says vitamin D is much more valuable than a tool to build bones and teeth. Researchers say vitamin D affects more than 1,000 genes, including ones that resist illness such as colds and even cancer.
“We never put together before that we get colds in the winter and not in the summer when we get more vitamin D in the summer,” Cannell said.
THE SNAG
Doctors who fight skin cancer fear that young people will start sunbathing — and sunburning — again, or use tanning beds to up their dose of vitamin D.
Dr. Susan Bayliss, professor of dermatology at the Washington University School of Medicine, recommends food supplements over increased sun
exposure. UVB and UVA sun rays remain culprits for skin cancer.
“The dilemma is that if you have really fair skin and red hair and freckles, it’s probably better to take your vitamin D in by mouth and put your sunscreen on,” says Bayliss, who also is director of pediatric dermatology and practices at St. Louis Children’s Hospital and the Center for Advanced Medicine.
People with more pigment (melanin) in the skin can tolerate more sun, she says.
AUSTRALIA’S DILEMMA
Heaney says that Australians, who have the highest rate of skin cancer in the world, years ago heeded the word about skin cancer and got out of the sun. But in only a few years, the rate of rickets — a disease of softened bones and bowed legs caused by vitamin D deficiency — increased.
Physicians who advocate more sun say vitamin D made with sunshine never reaches toxic levels. “Vitamin D gets to the useful level, then the sunshine destroys the surplus,” he says.
ELSEWHERE
As health experts wonder what to do with the new findings, they are examining vitamin D intake standards.
For example, the one-size-fits all approach is obsolete. Vitamin D intake recommendations change the closer you live to the equator. People who live in St. Louis don’t get the same amount of sun as southern neighbors, but we do get more sun that our northern states.
The Canadian Cancer Society, for example, last year raised its recommendation for daily vitamin D supplement intake to 1,000 IU per day, more than twice the 400 IU recommended daily for U.S. adults.
SUNSHINE
For some, getting more sun is a back-to-basics measure.
Dr. John Morley, head of geriatrics at St. Louis University, says, “In our nursing homes, people are supposed to be on 800 IU a day,” he said. Still, “about 40-50 percent are vitamin D deficient by the criteria you have to measure the vitamin D. For people 25, that’s not so important and can be corrected. But at 60 or 65 you’re more likely to have falls and deterioration in your functional status, more injuries, hip fractures.”
Nursing homes where he consults now put residents in the sun about 30 minutes a day. The policy led to fewer falls and fractures as well as better health and mood.
“Even with lousy sunlight, if you get people out a half-hour a day, and they’re not covered up and they get some sun, they’ll do OK,” Morley says. “Since we’ve been doing that, we’ve noticed a marked decrease in fractures in the nursing homes, and we now have a rule in the nursing homes, you have to check the vitamin D and make sure the people get (the vitamin) and calcium at an appropriate level.
“But so many people don’t get any sunlight, and that’s particularly true with older people.”
SAFE STEPS
Physicians agree on some issues:
– Vitamin D is essential and needs to be maintained and monitored.
– Sunbathing for a long time in direct summer sun is still a bad thing. “You can get outside, even wearing a hat and expose the arms,” says Dr. Veronica McGregor, an endocrinologist with St. John’s Mercy Medical Center in West County. “About 10 to 15 minutes two or three times a week. It doesn’t take much sun to get adequate vitamin D.”
– Check food labels on supplements because not all vitamin D is the same, Heaney says. You’ll find two types. The best is “cholecalciferol,” the form that occurs naturally and exists mainly in fish oils. It can be synthesized. The second type, “ergocalciferol, is an inexpensively produced vitamin D but may be only 30 percent as effective as the other form. A label that doesn’t specify is probably the lesser form, Heaney says.
– Cod liver oil is the best single source of vitamin D besides sunshine. One tablespoon can deliver 340 percent of the daily recommended vitamin D.
– Don’t rely on fortified dairy products. “Those levels were established (decades ago) to address problems with rickets in children,” Heaney says. “They don’t supply enough for an adult.”
– Tanning beds aren’t the answer. They may not be balanced properly between UVB and UVA rays. Too much UVA is not beneficial.
– Talk to your doctor about a vitamin D test. People most likely to have deficiencies are people who get little sun and anyone who has a family history of bone-density problems.
Source: St. Louis Post-Dispatch
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