Don't pop too many vitamins. Enthusiasm for vitamin pills is high, but evidence for their benefits is low. Try to get vitamins from foods and consider a multivitamin for insurance. Any woman thinking about getting pregnant should make sure to take a folic acid supplement. Women should get at least 1,000 mgs of calcium per day (1,200 mgs/day if you're past menopause) from food and/or supplements. Everyone should also get 800 international units of Vitamin D per day -- more than the federal "Recommended Daily Allowance."

-Dr. JoAnn Manson, chief of the division of preventive medicine at Brigham and Women's Hospital and professor of Medicine at Harvard Medical School