Nevermind milk: Who's got vitamin D?

The sun is not your friend.

These days, that’s the common wisdom: Stay out in the sun too long, and before you know it, cancer appears.

So, before heading to the beach, people undergo the ritual of slathering copious amounts of sunscreen on every inch of bare skin until a nice greasy sheen is reached.

Ironically, this trend of protecting  against the sun, and reducing exposure to a natural source of vitamin D, could be harmful to a person’s health. But experts don’t always agree on how to best supplement this important vitamin.

“Centuries ago, we were all working outside,” said Adit Ginde, M.D., who is an assistant professor at UC Denver’s School of Medicine and who has a master’s in Public Health. “Today, we’re becoming an increasingly indoor and inactive population.”

With all that time spent working indoors, something began to suffer: vitamin D production.
“Which, actually,” Ginde said, “is not a vitamin at all. It’s a hormone that is naturally produced by the body. Eighty to 90 percent of it is a product of sunlight.”

So, here’s how it works: When someone walks outside on a sunny day, the UV rays emitted by the sun hit the skin, setting off a series of chemical reactions that lead to the creation of vitamin D. Today, more and more people spend their time in cubicles or watching TV, which has a direct effect on the amount of vitamin D produced. “What we’ve seen is that vitamin D levels are down, and they’re continuing to go down,” Ginde said. “Sunscreen blocks out 99 percent of vitamin D production.”

Which, as Ginde and his colleagues found out, could be a bigger problem than previously thought.

“Scientists thought that vitamin D just had to do with bone health,” Ginde explained. “But in the last 10 years, we’ve realized that it is a hormone with effects throughout the whole body. Almost every tissue and body system has receptors (places that react to the chemical) for vitamin D. And nearly 1,000 human genes are affected, in some part, by this hormone.”

Ginde took part in a seven-year study that observed 3,400 adults above the age of 65, checking vitamin D levels.

“Those adults that had lower vitamin D levels, those that were in the bottom third, they were twice as likely to die,” said Ginde. “They were also two and a half times as likely to die by heart disease. And that’s where the real correlation is.”

Vitamin D is linked to several factors in the heart, including the stiffness of arteries, blood pressure control, and blood sugar regulation.

“The strongest predictor of death in these adults was vitamin D levels,” Ginde said.

This study was the latest done in a series that focus on vitamin D and its various effects on the body. One such study, released in February, looked at the relationship between vitamin D and the flu.

Ginde started his work in emergency medicine and asthmatics.

“We were seeing that people with asthma had worse outcomes after attacks if they had low levels of vitamin D, because they were getting more infections,” Ginde said.

Research has shown that vitamin D was, somehow, having an effect on the immune system.

“People with lower levels of vitamin D had a higher risk of getting the common cold or the flu,” Ginde said. “The Canadian government started looking at vitamin D and H1N1 and seeing if it (swine flu) could be prevented.”

There are flu shots and medicines and antibiotics available to fight off various infections, but it appears that vitamin D should be a priority.

Ginde is of the belief that one way to get vitamin D back in your system is simple: Go outside.

“Getting 10-15 minutes of unblocked sunlight on your bare arms and legs a few times a week can bring up vitamin D levels,” Ginde explained.

That time spent outside in the sun is equivalent to drinking 30 cups of fortified milk.
However, the American Academy of Dermatology does not necessarily agree. The organization states that a person’s source of vitamin D “should not be obtained from unprotected exposure to ultraviolet radiation.”

According to the Academy, “There is no scientifically validated, safe threshold of UV exposure that allows for maximum vitamin D synthesis without increasing skin cancer risk.” So, while vitamin D sources do exist naturally, there may be a better way to get your fix.

Sunny Linnebur, Pharm.D., Associate Professor of UC Denver’s School of Pharmacy, thinks that, while the source is important, there are other factors surrounding the issue and that patients should speak to their physicians about the best way for them to supplement vitamin D.

“Vitamin D levels need to be checked—if they’re too low, simply taking an over-the-counter dosage may be ineffective,” said Linnebur.

 Sure, the easiest way is to spend some time with good ’ol Mr. Sun. However, before making it your best and closest buddy, talk to a physician and find out your vitamin D levels.