Our skin naturally contains something called 7- dehydrocholesterol. When exposed to UVB rays from the sun, this organic molecule magically becomes— drum roll, please— vitamin D. Here is where things get complicated: A small but vocal group of doctors are convinced that vitamin D deficiency is fast becoming a public health epidemic again. (Indeed, some studies have shown that rickets, once considered a thing of the past, is on the rise.) One possible cause? A lack of direct sun exposure. Th e idea is that once we all got hip to the dangers of UV light (burning, premature aging, age spots, and skin cancer, to name a few), we stopped getting enough sun to produce adequate levels of vitamin D. Th at's a pretty controversial notion.
Before you slather on the baby oil, you should know that studies have shown that regular use of sunscreen does not signifi cantly interfere with your body's ability to produce vitamin D. Th ere is also no consensus as to what constitutes an adequate level of vitamin D, and the ideal amount may be different for diff erent people. If you're concerned about getting enough, talk to your doctor about taking a supplement. But please, don't sit in the sun unprotected. Also, skip the tanning beds altogether, which emit mostly UVA rays anyway. (Remember, it's UVB rays that produce vitamin D.)
Skin Enemy #2: UV Radiation
We all know that too much sun can make your skin look like a vintage leather handbag or, worse, like Magda, the scary lady from the Ben Stiller/Cameron Diaz hit There's Something About Mary. But UV damage is more than just aesthetic. Th e sun's rays penetrate deep into the skin— all the way down to your DNA. Recent research shows that UV radiation can temporarily alter the function of white blood cells, meaning that even mild sunburns can suppress the immune functions of the skin. And if you've had sunburns in the past (who hasn't?), you're already at greater risk of developing melanoma, the deadliest type of skin cancer. Th at's why both the American Academy of Dermatology and the American Medical Association recommend staying out of the sun between 11 AM and 2 PM as well as wearing sunscreen and protective clothing when you're outdoors. It is also why most dermatologists equate sunbathing with devil worship. But I'll let you in on a little secret: I like being tan. Having some color makes me feel taller, thinner, healthier, and more beautiful. UV light can even guard against seasonal affective disorder (SAD), better known as the winter blues.
Th at is why I'm not going to tell you to stay indoors during the day or to wear long sleeves in the summer. In my experience the less realistic the advice, the less likely you are to follow it. For example, when my osteopath told me the only answer to chronic hip pain was to ditch my high heels for flats, I told her to forget it. There's no way I'm giving up my four-inch platforms. (Besides, my husband is 6'2", and I want to be able to look him in the eye!)
The thing is, you don't have to wear a burka to be safe in the sun. Certain foods— green tea and tomatoes in particular— have been shown to boost your skin's ability to fi ght UV rays and sunburn, so incorporating them into your diet, especially before you hit the beach or spend an afternoon on the tennis courts, can improve the protection you'll get from sunscreen alone. For much more info on sun damage, UV- fi ghting foods, and even fake tanning tips, turn to Chapter 6.