A Supplements Guide: What You Need to Stay Healthy

Vitamin D

The Big Picture: This concern was raised by the stir surrounding The UV Advantage (ibooks, Inc., 2005) a book by Michael Holick, PhD, MD, and Mark Jenkins, which claims that fear of skin cancer prevents us from getting the sun exposure we need to naturally produce vitamin D. Sunlight is essential for vitamin D production in our bodies. However, several minutes a few times weekly is all you need, explains Darrell Rigel, MD, a clinical professor of dermatology at New York University Medical Center and past president of the American Academy of Dermatology. "You can get this walking to and from your car or taking out the trash," Dr. Rigel says. "Plus, there's no data that show wearing sunscreen daily puts you at risk for D deficiency."

Also fueling this fear is a recent study that suggests taking D supplements may help prevent colon, breast, and other cancers. The researchers recommend high doses of D: 1,000 mg daily. However, cancer experts aren't rushing to advocate this. "These findings need to be confirmed by more studies before there's a major shift in guidelines," says B. Jay Brooks, MD, chairman of the hematology/oncology department at the Ochsner Clinic Foundation in Baton Rouge, Louisiana. The upper limit is 2,000 mg; high levels can put you at risk for heart arrhythmias and kidney problems.

Bottom Line: Spending five minutes in the sun daily (even with sunscreen) can ensure that you get enough to produce vitamin D. To supplement, the amount found in a multivitamin (the RDA of 400 IU) is sufficient.