Calcium Supplements: Which Type of Calcium is Best?
When searching store shelves for calcium supplements, it can be difficult to translate the information on each label and decide which is the ideal calcium supplement for your individual needs and lifestyle. There are a variety of calcium types commonly used for supplementation, including calcium citrate, gluconate, lactate, and carbonate.
Calcium carbonate and calcium citrate are the two forms of calcium most likely to be included in a supplement purchased over-the-counter. Calcium carbonate supplements should be taken with meals whenever possible, as stomach acids assist in the absorption of this type of calcium. Calcium citrate supplements can be taken any time of day, with or without food.
One source of calcium that is often contained in less-expensive, generic brands of supplements is unrefined calcium carbonate. This calcium source comes from ground oyster shells, dolomite (clay), limestone, and bone meal. Avoid supplements derived from these sources, as they have been known to contain toxic substances, including mercury and lead. On the opposite end of the price spectrum is chelated calcium. There is debate in medical communities as to whether this form of calcium is more easily absorbed by the body than other forms of the mineral. As of now, chelated calcium has no proven additional benefit, and it costs significantly more than other forms of calcium.
When comparing calcium supplements, the source of the calcium is far less important than the amount of elemental calcium the product contains. Elemental calcium is simply the amount of calcium available for use by the body. Not all types of supplemental calcium can be absorbed by the body, which makes determining the level of elemental calcium extremely important. Some brands of calcium supplements list the elemental calcium right on the label. For brands that do not, there is a simple and accurate calculation that should be done before you make your purchase.
Find the "Nutrition Facts" box on the back of the supplement label, and look for the line that lists calcium. This figure tells you the percentage of calcium one dose of the supplement contains - relative to the total recommended daily value. The percentage is based on a daily recommendation of 1,000 mg of elemental calcium. If the label says 70%, for example, then the supplement provides 70% of 1,000 mg or 700 mg.
Another important item to look for on the label is "USP". This is the logo for the US Pharmacopeia - an organization that sets quality standards for all drugs, supplements, and healthcare products manufactured and sold in the United States. Compliance with USP standards is voluntary, but if you choose a supplement with the USP logo, you know that it meets certain minimum standards with respect to the product’s purity, quality, and effectiveness.
These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.