Why do I need calcium?
For all of the attention and acclaim calcium gets as a bone builder, that's just one of its jobs throughout the body. Among other things, the mineral plays a crucial role for the nerves and the heart. Recent studies have shown that calcium can help lower blood pressure, and there's some evidence that calcium can help prevent cancer of the colon and rectum. Calcium is so important that you can't function without it; if you aren't getting enough in your diet, your body will start stealing it from your bones. If your bones lose too much calcium, they can become brittle and weak, a condition known as osteoporosis.
Getting your full supply of calcium -- through foods or supplements -- will go a long way towards protecting your bones and your overall health.
How much should I be getting?
According to the guidelines released by the Institute of Medicine in 2010, adults between the ages of 19 and 50 should get 1,000 mg of calcium every day. If you're over 50 -- an age when bones can start to seriously thin -- you should get at least 1,200 mg. Teenagers and women who are pregnant or nursing need 1,300 mg.
Calcium supplements have recently been linked with a small absolute risk of heart attack, which has prompted some experts to call for people to get most of their calcium from diets rather than supplements. If you are unable to meet the requirements and you must take a supplement, experts say it's best not to take calcium pills of more than 500 mg per tablet in one dose. By breaking up the supplements over the course of a day, calcium levels in the blood shouldn't increase beyond normal.
What's the best way to get calcium in my diet?
Dairy foods are an excellent source of calcium. An 8-ounce glass of milk (or a cup of yogurt or a thick slice of cheese) gives you 300 mg; get three servings and you're practically set for the day. If you don't like dairy, you can get just as much calcium from fortified juices. Other possible sources include tofu (the kind made with calcium sulfate, 435 mg per half cup), broccoli (180 mg per cup), and canned salmon (180 mg per 3 oz.)
Should I take a supplement?
Possibly, but it's best to get calcium through your diet. Foods that contain calcium tend to be loaded with other vitamins and nutrients that can be a big boost for your health. The vitamin D in fortified milk, for instance, will help your bones absorb calcium.
If you're at high risk for osteoporosis or if you're pregnant or nursing, you should ask your doctor if a calcium supplement makes sense. Because calcium supplements are bulky, you won't find the mineral in a regular multivitamin. Tums EX has 300 mg calcium in each tablet. Viactiv offers 500 mg.
Can I get too much calcium?
The Institute of Medicine has set the safe upper limit at 2,500 mg a day for adults. That's a pretty hefty amount that you're unlikely to reach unless you're really downing a lot of supplements. Symptoms of an overload of calcium may include nausea, loss of appetite, vomiting, constipation, thirst, and frequent urination. It's also possible that taking supplements can increase the risk of kidney stones.
National Institutes of Health. Office of Dietary Supplements. Calcium. 2010. http://ods.od.nih.gov/factsheets/Calcium-QuickFacts/
Institute of Medicine. Dietary reference intakes for calcium and vitamin D. 2010. http://www.iom.edu/Reports/2010/Dietary-Reference-Intakes-for-Calcium-and-Vitamin-D.aspx
Linus Pauling Institute at Oregon State University. Calcium. 2010. http://lpi.oregonstate.edu/infocenter/minerals/calcium/