Calcium Supplements: What To Look For (cont.)
These compounds contain different amounts of elemental calcium, which is the actual amount of calcium in the supplement. It is important to read the label carefully to determine how much elemental calcium is in the supplement and how many doses or pills to take.
Calcium supplements are available without a prescription in a wide range of preparations and strengths, which can make selecting one a confusing experience. Many people ask which calcium supplement they should take. The "best" supplement is the one that meets your needs. Ask yourself these questions:
Other Important Things to Consider
Purity: Choose calcium supplements with familiar brand names. Look for labels that state "purified" or have the USP (United States Pharmacopeia) symbol. Avoid calcium from unrefined oyster shell, bone meal, or dolomite without the USP symbol, because it may contain high levels of lead or other toxic metals.
Absorbability: Most brand-name calcium products are absorbed easily in the body. If you are not sure about your product, you can find out how well it dissolves by placing it in a small amount of warm water for 30 minutes and stirring it occasionally. If it hasn't dissolved within this time, it probably will not dissolve in your stomach. Chewable and liquid calcium supplements dissolve well because they are broken down before they enter the stomach.
Calcium, whether from food or supplements, is absorbed best by the body when it is taken several times a day in amounts of 500 mg or less, but taking it all at once is better than not taking it at all. Calcium carbonate is absorbed best when taken with food. Calcium citrate can be taken anytime.
Tolerance: For certain people, some calcium supplements may cause side effects such as gas or constipation. If simple measures (such as increasing your intake of fluids and high-fiber foods) do not solve the problem, you should try another form of calcium. Also, it is important to increase the dose of your supplement gradually: take just 500 mg a day for a week, then slowly add more calcium. Do not take more than the recommended amount of calcium without your doctor's approval.
Calcium Interactions: It is important to talk with a doctor or pharmacist about possible interactions between your over-the-counter and prescription medications, and calcium supplements. For example, calcium supplements may reduce the absorption of the antibiotic tetracycline. Calcium also interferes with iron absorption. So you should not take a calcium supplement at the same time as an iron supplement - unless the calcium supplement is calcium citrate, or unless the iron supplement is taken with vitamin C. Any medication that you need to take on an empty stomach should not be taken with calcium supplements.