Vitamin D

Courtesy of Ocean Potion; Dr. Dennis Gross; BrownberryVitamin D sure is a hot topic these days. About one third of the U.S. population has low levels, and it's been touted as a cure-all for everything from depression to heart disease and skin cancer. With all the talk going on, there's a lot of back-and-forth over the full range of D's superpowers.

But most recently added to the list? Mega anti-ager.

Here's the thing: We already know that skin is a crucial catalyst and gateway for vitamin D to get to where it needs to in the body. "Vitamin D is primarily synthesized in skin exposed to UV light, if not obtained by diet or supplements," explains Jean Y. Tang, M.D., Ph.D., assistant professor of dermatology at  Stanford University School of Medicine .

And since over time, the skin's ability to create vitamin D decreases (up to 75 percent from the age of 20 to 70) you'll eventually have to pop more vitamin D supplements to reach standard levels than when you were younger. (That's one of the reasons why Grandma is more likely to be diagnosed with osteoporosis, because of D's crucial role in bone health.)

But does D play a much more superficial role? "Vitamin D is a key ingredient for beautiful looking skin," says Dennis Gross M.D, a dermatologist in New York City and creator of his namesake skincare line. "Skin, like all organs, needs vital vitamins to function properly-and vitamin D is one of them."

Dr. Gross has spent the last few years researching the D-skin connection, really one of the only experts to do so in the dermatology community, making him a lone ranger of sorts. And the benefits he's uncovered from poring over the existing vitamin D research and observing his own patients' experiences are expansive. Having sufficient vitamin D in the skin helps minimize acne, boost elasticity, stimulate collagen production, enhance radiance, and lessen lines and the appearance of dark spots, he says. It's this laundry list, plus anecdotal evidence from seeing patients day in and day out at his NYC office, that led him to create skincare with D right in the bottle. "Many of my patients have vitamin D deficiencies as a result of avoiding the sun and wearing a daily sunscreen in fear of premature aging and cancer," he says. "Together, we noticed that their skin had a sallow and dull appearance, which I believed to be an adverse effect from low levels of vitamin D."

After heading to the lab, Dr. Gross says he saw that popping a D pill wasn't the only way to make sure you got enough of the much needed to your complexion-the skin could get it directly from a product. "I came up with a formula that I immediately began testing on patients and then witnessed a dramatic reversal of symptoms, even after one application," he says. "I then began applying Active Vitamin D Serum-Oil to patients who weren't deficient and noticed similar beneficial results. The immediate results were enough to convince anyone who may have originally been skeptical."

So, how does it work? "It already contains an active form of vitamin D2 (aka ergocalciferol, a plant source of vitamin D) and doesn't require sunlight to start giving skin the benefits of vitamin D," says Dr. Gross. "Taking a Vitamin D supplement orally, while benefiting the body, will not give you the same skincare benefits as daily, topical application." And to be clear, a topical D product won't raise the levels in your body, so it's not a substitute for supplements or vitamin D-rich foods.

Beauty Foods With Vitamin D 

Experts don't dispute the fact that vitamin D plays a crucial and positive role in the skin. "Vitamin D is important for control of the natural immune protective mechanisms of the skin," Richard L. Gallo, M.D., Ph.D., chief of the division of dermatology at the University of California in San Diego. It's just that many docs aren't yet convinced that slathering on creams can increase D in the skin. "In order for vitamin D to play its role in the body it has to go through a process called hydroxylation, which means it has to pass through the liver then the kidney to turn into an active form that's then circulated around the body," says Kathleen Fairfield, M.D., assistant professor at Tufts University School of Medicine. "So, even if you apply a topical form of vitamin D, it has to be absorbed, hydroxylated, and then sent back to the skin."

Vitamin C Makes You Look Younger  

This is where the topic of D's role in the skin gets sticky. Dr. Gross counters this point by explaining that vitamin D2 is sourced from a plant, and therefore has already been activated by the sun. Dr. Fairfield maintains that D2 still has to go through the same process in the body in order to be effective.

The bright side? If you can give skin a boost of D from the outside in, great. If not, you're still benefiting from the products' (be it from DG Skincare or other D-infused products) main prettifying purpose-let it be sun protection, hydration, exfoliation even a faux-glow. But regardless, you still need to practice sun safety and fill your plate with foods naturally rich in D (like tuna or salmon) or those that get it added in (like cereal or milk) or pop a 600-1000 IU supplement to be sure that every day body, skin, the whole shebang get some D.