Cancer Questions: Vitamin D Deficiency
"I know UV rays can cause cancer, but I've read people are vitamin D-deficient from lack of sun exposure. What's the best solution?" —Lisa Gartner, 22, Washington, D.C.
Confusing, right? Both things are true. Nearly three quarters of us have insufficient D, a study from the University of Colorado School of Medicine in Denver notes. That's problematic, because lack of D may up your odds of heart disease and osteoporosis—while higher D levels are associated with lower incidence of breast and colon cancer, says Henry W. Lim, M.D., chairman of the department of dermatology at Henry Ford Hospital in Detroit. But your need for D is not a free pass to sunbathe. "The safest way to get vitamin D is through diet and supplements," Dr. Lim says. Current guidelines for women younger than 50 are 200 international units daily (fulfilled with 2 cups of fortified milk or only 1 ounce of salmon). But scientists say we may need at least 800 IU a day to reap D's disease-protecting benefits. Don't know your levels? Ask for the simple blood test at your next physical. Your doctor may suggest a multivitamin.