Vitamin and mineral supplements are a good thing. But too much of a good thing can negate any health benefits — and even pose health risks. With calcium, vitamin A and vitamin D, “more is not necessarily better,” cautions Melissa Young, MD, of the Center for Integrative Medicine. 1. Calcium Why it matters: Calcium plays a critical role in building and maintaining healthy bones. For decades, experts have recommended high-dose calcium supplements to prevent osteoporosis. The bone-thinning disease is responsible for fractures that cause many elderly men and women to lose their independence — and sometimes their lives. How too much can hurt: “More and more studies are showing increased risks for heart attack and stroke among men and women taking calcium 1,000 to 1,200 milligrams (mg) per day as directed,” says Dr. Young. Researchers believe that without adequate vitamin D to help absorb it, the extra calcium settles in the arteries instead of the bones. There, it helps form plaques that threaten the heart and brain. Excess calcium can also cause muscle pain, mood disorders, abdominal pain and kidney stones. What to do about it: “We recommend trying to get your calcium from food,” says Dr. Young. “The body absorbs and utilizes calcium better from food than from supplements.” Probably the best source of dietary calcium is fat-free organic Greek yogurt. It gives you 450 mm of calcium per serving, plus vitamin D and protein, and two servings fulfill your calcium needs for a full day.