Q. I have recently read that calcium supplements can be dangerous when not taken with magnesium. Also, that the ratio of calcium to magnesium should be 2:1 or lower. Will you please have your experts answer whether this information is correct? I should be increasing my calcium for bone health but am worried about the negative effects.

ABess Dawson-Hughes, MD, director of Tufts HNRCA Bone Metabolism Laboratory, answers: I dont know of any danger of taking calcium without magnesium. Of course, adults (and others) should meet the requirements for both minerals, but it is not important to take the two together.

The Recommended Dietary Allowance (RDA) for calcium is 1,000 milligrams daily for women up through age 50 and men through age 70, increasing to 1,200 milligrams daily for women ages 51 years and up and men ages 71 and older. The RDA for magnesium is 400 milligrams for men and 310 milligrams for women daily for ages 19-30, rising to 420 milligrams daily for men and 320 milligrams for women for ages 31 years and older.