Where Should You Get Calcium?
The ideal way to get calcium, like any nutrient, is from foods. Dairy products such as milk, cheese, and yogurt are the best and most obvious sources. One 8-ounce cup of low-fat, plain yogurt contains 415 mg of calcium -- more than a third of the daily recommendation for most age groups. An 8-ounce glass of nonfat milk will provide you nearly 300 mg of calcium. And 1.5 ounces of part-skim mozzarella has 333 mg.
Even if you're lactose intolerant, you can still enjoy your milk by choosing one of the lactose-free or lactose-reduced dairy products available at your local supermarket. Another option is to take lactase enzyme drops or tablets before you eat dairy.
Several non-dairy foods are also good sources of calcium, including:
Food Calcium content per serving
Calcium-fortified orange juice, 6 ounces 375 mg
Canned sardines with bones, 3 ounces 325 mg
Firm tofu made with calcium sulfate, 1/2 cup 253 mg
Canned salmon with bone, 3 ounces 181 mg
Calcium-fortified breakfast cereal, 1 cup 100-1,000 mg
Boiled turnip greens, 1/2 cup 99 mg
Cooked fresh kale, 1 cup 94 mg
Taking Calcium Supplements
If you're not getting enough calcium from food alone, your doctor might recommend a supplement.
Calcium supplements come in two main forms:
- Calcium carbonate -- found in products such as Caltrate 600, Os-Cal 500, Viactiv Calcium Chews, and store brands
- Calcium citrate -- found in supplements such as Citracal
Calcium carbonate is also commonly found in over-the-counter antacids, such as Rolaids and Tums.
You need to take calcium carbonate with food, because it's easier for your body to absorb that way. You can take calcium citrate on an empty stomach or with food.
To maximize your absorption of calcium, take no more than 500 mg at a time. You might take one 500 mg supplement in the morning and another at night. If you take a supplement that also contains vitamin D, it will help your body absorb calcium more efficiently.
Avoid eating these foods when you take your supplement, because they can interfere with calcium absorption:
- Caffeinated coffee and soda
- High-salt foods
Calcium Supplement Side Effects
Before taking calcium supplements, you need to be aware of the side effects of high calcium intake, which include:
- Gas or bloating
- Kidney stones
Calcium can also decrease absorption of some medications, including osteoporosis medicines, thyroid medicines, and some antibiotics. Ask your doctor if your medicines may interact with calcium, or to be safe, just don't take them at the same time. Taking calcium and vitamin D supplements with thiazide diuretics may increase the chance of kidney stones.
A June 2012 study in the journal Heart also linked calcium supplements with a greater likelihood of heart attacks. This finding may be of special concern to anyone who is already at risk for heart disease.