The Vitamin D And Sun Debate

We set the record straight once and for all!

| August 7th, 2012

Tired of hearing about Vitamin D? This much-talked-about topic was heralded by the New York Times as the “supplement of the decade.” But for all the good D can do for your body (like build strong bones, ward off depression, heart disease and possibly even cancer) the mere fact that people are ditching their sunscreens and risking skin cancer to soak up vitamin D-strong solar rays is particularly worrisome. And despite all the hoopla about vitamin D, the information still seems contradictory and ill D-fined.

MORE: Vitamin D and Glowing Skin

So let’s clear up the confusion. Here’s what we can tell you about vitamin D:

D stands for Desirable

Our bodies actually produce the stuff, but like most things that seem to peter off with age, our body’s ability to churn out vitamin D is one of them. D regulates calcium as well as phosphorous levels in the blood and helps with the body’s absorption of calcium.

“One of the greatest misunderstandings is that most Americans get enough vitamin D and don’t need to be concerned about it,” says Walter Willett, M.D., chair of the department of nutrition at Harvard School of Public Health in Boston, Massachusetts. “But the evidence is quite strong that many people will benefit from getting even higher levels of D than what’s currently recommended.”

QUIZ: Just How Healthy Are You?

How Much Does It Take?

In November 2010, The Institute of Medicine (IOM) in Washington D.C. released new guidelines for how much D is necessary daily: 600 IU for those under 70 years-old; 800 IU for those older than that.

But not everyone agrees with those digits.

“I recommend getting a minimum of 1000 IU units a day,” says Michael Roizen, M.D., YouBeauty co-founder and chief wellness officer at the Cleveland Clinic in Cleveland, Ohio. “Get a blood test to be sure of your levels, especially if you have any question that you might be low.” Why the inflated number? “For most people, their D level should be 50 to 80 nanograms, so if they’re over the age of 50 that requires 2000 IUs of D or more daily to reach. So no matter what age you are, you should be getting at least 1000 IU a day,” says Dr. Roizen.

The Sun Is Not The Answer

“Sunlight is the main natural source of D, but getting adequate amounts of sun without increasing one's risk of skin cancer is just too complicated for most people,” says Willett.

Roizen agrees that raising D levels from the sun alone isn't so clear cut. While it’s definitely an efficient (and free!) way to get D, you’d have to show some bare, sunscreen-free skin to direct sun for about 10 to 15 minutes—every, single day. (He notes that skipping the sunscreen on your legs while you’re wearing a sun dress should suffice.) But—and it’s a BIG but—this method of going sunscreenless doesn’t work whenever you darn well please.  To trigger enough D production, you’d have to be outside when the sun is at its strongest—between April and October—and during prime skin-scorching hours (12 to 3 pm). Oh, and your address matters too; if you’re north of Atlanta or Los Angeles it’s unlikely you’ll get enough D from the sun alone. Complicated, right?

“Creating vitamin D in the skin requires a certain amount of energy,” explains Roizen. “Being outside when most people are—before or after work—is simply not going to get you enough of it.”

The other super-obvious red flag of soaking up the sun sans sunscreen: skin cancer.

MORE: Skin Cancer & Ethnic Skin

There’s no question that constant ultraviolet exposure both intentional (in a bikini, sprawled on the beach) and incidental (walking to and from your car a gazillion times a day) can lead to DNA abnormalities that cause the formation of tumorous cells. Broad-spectrum sunscreens (which you absolutely should be wearing as it’s the number-one way to prevent skin cancer), shield you from UVB—those rays that cause painful sunburns. But they’re also the same wavelength needed for D-synthesis, which is why most doctors say you might as well get D in pill form and be done with it… 

Pop A Pill

There are only a handful of foods that naturally contain D and they aren’t the ones you’d snack on daily—think salmon, swordfish, sardines. “Vitamin D is naturally present in only a few foods; fish being the most important, but the amounts are too low to make much difference,” says Dr. Willett.

MORE: Beauty Foods Rich in Vitamin D

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