If you have trouble sometimes picking out a good calcium supplement, you are not alone. Choosing a calcium supplement can be a frustrating experience, even for health care professionals. The reason is simple. In U.S, calcium supplements are prepared and sold in different formulations, each claiming to be the right one for you. The fact that there are as many brand names as there are formulations makes it even more confusing for an average consumer. However, the situation is not entirely hopeless. Knowing what you should look for when shopping for a calcium supplement can make your experience less frustrating.

The first thing you should do when shopping for a supplement is take a few minutes to read the "supplement facts" label found on the supplement bottle. On it, you will find the serve size or dose for the supplement, the kind of calcium compound it contains, amount per serving, and percent daily value. Percent daily value is simply the percentage of the daily value provided by one serving.

Secondly, determine the calcium content per serving of the supplement. You can do so by identifying the kind of calcium compound used in the supplement. Different calcium compounds have different amounts of calcium (or elemental calcium). For example, calcium carbonate is 40% calcium; dicalcium phosphate is 38% calcium; calcium citrate is 21% calcium; calcium lactate is 13% calcium by weight and calcium gluconate is 9% calcium. What this means is that if you take 500 mg of calcium carbonate, for instance, you will get 200 mg of calcium. By contrast, you will have to take at least 950 mg of calcium citrate in order to get the same amount of calcium.

Next, consider how well the supplement dissolves. This is what sets apart good calcium supplements from bad ones. If the supplement does not dissolve well in your stomach, you are unlikely to get maximum benefit from it. To test how well the supplement dissolves, place a pill in a cup containing warm water. Let it sit for 30 minutes while stirring occasionally. If it does not dissolve well after 30 minutes, it is unlikely to dissolve well in your stomach.

Absorbability is also an important feature of a good calcium supplement. Calcium carbonate is well absorbed by most people, but calcium citrate is often recommended for those with digestive or absorption problems. You can also improve absorption of any calcium supplement by taking it in doses of 500 mg or less and with vitamin D. Calcium carbonate should be taken with food while calcium citrate can be taken any time during the day.

Good calcium supplements meet certain purity standards indicated by the use of the abbreviation USP, which stands for United States Pharmacopeia. Choose only supplements that have this symbol on their labels. Avoid calcium from unrefined oyster shell, bone meal, or dolomite without the USP symbol; they may contain high levels of lead or other toxic metals.

Finally, check how well you tolerate the supplement. Some calcium supplements produce side effects such as constipation, gas, and stomach upset. If you develop any of these side effects, try the steps discussed above under absorbability. If those steps do not help you, try a different supplement. You may also consult with your doctor or pharmacist.

Anyone looking for a calcium supplement can easily find one in the stores; picking out the right one for you is a different story. So, before you buy, read the "supplement facts" label carefully. Determine the calcium compound in the supplement and its calcium content. Test how well it dissolves and your level of tolerance for it. Choose supplements with the USP abbreviation on their labels. If you develop side effects from your supplement, try a different one, or consult with your doctor.