Yours is a very good question. Last year a review of data from a large study found a slight elevated risk for heart disease and stroke in women who took supplements of calcium with or without vitamin D. What are we to do with this information?
First off, the best place to get all your nutrients is from food. Anyone worth their weight in nutrition credentials will tell you to go to milk and other calcium-rich foods. The reality is, few women drink 3 to 4 glasses of milk a day and their diets are far too low in this mineral. If you aren’t getting enough calcium from dietary sources, you risk the crippling disease of osteoporosis and possibly colon cancer and high blood pressure.
Second, nutrition is not a black-and-white science. Studies flip flop on topics, so you must look at where the weight of the evidence lies. Each study is like a thread in a tapestry. What does the tapestry say. In this case, there are many more studies showing calcium is safe and important for bone health and only a few that suggest it might slightly elevated heart disease risk.
The bottom line: On the days when you don’t consume at least 3 calcium-rich foods in the daily diet, take a moderate-dose calcium (preferably with magnesium) supplement. You only need to fill in the gaps between recommended intake and your dietary intake, not supply the entire 1,200 milligrams of calcium from a pill. I recommend one that supplies these two minerals in a 2:1 ratio, or about 500 milligrams calcium and 250 milligrams magnesium.