The link between sun exposure and skin cancer is undeniable. Yet research has shown that vitamin D—the “sunshine vitamin” the body makes when sun hits skin—may protect against some cancers. Oncologist Howard Kaufman of Rush University Medical Center and Walter Willett, chair of the nutrition department at Harvard School of Public Health, advised us on safely getting our vitamin D.
Know Your Risks
There are two classes of skin cancer: melanoma (the more deadly) and nonmelanoma (more common but with a 95 percent cure rate). Though not all melanomas are caused by sun exposure, sun seems to play a role in some. “Prevention has to be individualized,” Kaufman, a melanoma specialist, says. He tells his patients to limit their exposure if there is a family history of nonmelanoma skin cancers, such as basal and squamous cell cancer, or melanoma skin cancer.
Eat Your Vitamins
It’s easy to incorporate vitamin D into your diet. Oily fish, like salmon, mackerel, herring and sardines, are high in the vitamin, as are eggs and fortified cereals and milk. There are limits to relying on diet for vitamin D, however: Unless you eat fish every day, you won’t come close to the 600 IU (international units) a day that the Institute of Medicine recommends.
Vitamin D Supplements
“The amount of vitamin D we get from 20 minutes in the sun depends on our skin color, time of year, location and how much skin is exposed,” Willett says. For this reason—and especially if you live at a northern latitude and work indoors—taking a supplement is a more reliable way of getting vitamin D.* (Not to mention safer if you have a family history of melanoma.) Two years ago the Institute of Medicine reevaluated its recommended daily intake level for vitamin D and tripled it, from 200 IU a day to 600 IU. (It rose to 800 IU a day for those over 70.) Some doctors, including Willett, think most people would benefit from 1,000 to 2,000 IU a day. (No toxicity has been documented at levels of less than 10,000 IU a day.) The jury is still out on which form is better, but Willett prefers the natural form of the vitamin, known as D3 (or cholecalciferol). Also, taking vitamin D with meals is usually recommended, since the fat-soluble vitamin is absorbed better when consumed with food.
It can be hard to avoid the sun on vacation, especially when you’re hiking, swimming or snorkeling. Kaufman recommends covering up with a hat and a long-sleeved shirt. “In general I think clothing works better than sunblock,” he says. That noted, sunblock can be an effective source of protection. Consider trying a broad-spectrum type, like Neutrogena’s UltraSheer Dry-Touch, which contains Helioplex, a substance said to block both UVA and UVB rays. Remember to reapply every two hours, no matter how high the SPF. Use a broad-spectrum lip balm, too, and be sure to protect your eyes with 100 percent UVA- and UVB-absorbing sunglasses.
Soak It Up
If you don’t have a family history of melanoma and prefer getting your sunshine vitamin from the sun, consider holding off on the sunblock for a short time in the morning. “Sunblock stops the ultraviolet sun rays that activate vitamin D in our skin,” Willett says. Just know that frequent sun exposure causes changes in the skin’s basal and squamous cells as well as wrinkling, so there’s reason to keep the sunblock (or umbrella) within reach.
- *Consult your physician before taking any supplement. Use all supplements as directed.
- NOTE: Information may have changed since publication. Please confirm key details before planning your trip.
- Published: March 2014