Posted May 6, 2010
San Francisco — One April day after weeks of rain, Daniel Jiminez took a detour on his way to class: Dolores Park in San Francisco.
He needed the sun.
“I know what they say about skin cancer, but I just feel better when I’m warm and tan,” said Jiminez, 24. “I’m sorry, but I’d rather be happy.”
Turns out doctors are coming around to his point of view. After decades of slathering on SPF protection, more people are discovering through routine medical screens that they have deficiencies in vitamin D — a hormone produced in the body by sun exposure.
As a result, doctors are seeing a resurgence of rickets and are concerned with osteoporosis in adults over 50. But for most people with low vitamin D levels, symptoms are hard to pinpoint: feeling tired, sluggish or a general malaise.
Known for causing bowed legs and fractured bones primarily in children, rickets all but disappeared in the United States in the 1930s as diets improved and vitamin D was added to certain dairy products.
But in the ensuing decades, as people turned to increasingly stronger sunscreen to ward off melanomas, and work shifted from predominantly outdoor activity to office work, vitamin D has been slowly slipping out of our systems, according to Dr. Michael Holick of Boston University Medical Center, who writes in his new book “The Vitamin D Solution” that lack of vitamin D can lead to heart disease, cancer, depression, insomnia, diabetes, chronic pain and perhaps autism.
“We’ve done studies that show that people living at higher latitudes with less sun are at higher risk of vitamin D deficiency,” Holick said.
Levels in breast milk
Another study of lactating women in South Carolina showed negligible levels of vitamin D in their breast milk.
“Evolutionarily, that makes no sense when our forefathers made thousands of units of it a day,” Holick said.
National guidelines have not kept up with the dipping D levels, he said.
Federal health experts currently recommend between 200 and 600 international units of vitamin D a day. But those benchmarks are due to change this summer, as the Institute of Medicine’s Food and Nutrition Board responds to the new research about vitamin D.
“It should be 10 times that,” Holick said.
While vitamin D is found in some foods, such as wild caught salmon, fortified milk and mushrooms, it’s not enough to replenish what’s missing.
Receiving serious attention
Holick has caught some flack from dermatologists for suggesting that 15 to 30 minutes of sun exposure on the legs and arms per day, a few days a week, can restore vitamin D levels. Vitamin D created via sun exposure versus supplements lasts twice as long in the body.
Despite being fired from Boston University’s department of dermatology in 2004, Holick is now getting more serious attention because of his stance. He’s Boston University’s lead vitamin D researcher, studying the vitamin’s effect on genes.
“Just a light pink color, before burning, then put on the sunscreen, will do it,” he said, adding that the face should always be protected.
Holick keeps his own vitamin D levels up with three glasses of milk, a multivitamin and a 2,000-unit vitamin D capsule each day.
He plays tennis, gardens and cycles each week for brief periods with sunscreen only on his face.
But pills can also do the trick, and that’s what more doctors are suggesting.
Patients can ask doctors to do a special screen for vitamin D (the 25-hydroxyvitamin D test) that costs about $200 and may or may not be covered by insurance. The magic number doctors are looking for is at least 30, which stands for nanograms per milliliter.
Prescribing further units
If levels are too low, doctors typically prescribe 50,000 units once a week for eight weeks to fill up the tank, then every two weeks thereafter. The next two months, patients take anywhere from 4,000 to 6,000 units until a healthy vitamin D level is reached.
Maintenance is considered anywhere from 1,000 to 3,000 units a day.
“It’s kind of a mixed message: Do you want cancer or do you want brittle bones?” said Wren Wolf, 21, a friend who joined Jiminez on his impromptu Dolores Park picnic.
“I think it all boils down to everything in moderation.”
E-mail Meredith May at mmaysfchronicle.com.