Calcium deficiencies can result from mineral depletion in the body relating to age, stress, lactose intolerance or disease. Sufficient calcium intake replaces calcium lost every day through the skin, nails, hair, sweat and urine. If you cannot get the daily-recommended 1,000 to 1,200 mg of calcium, you may need supplements to maintain optimum bone density and to prevent the risk of osteoporosis. Calcium supplements are made by combining calcium with various salts, forming compounds that contain different amounts of elemental calcium, the calcium your body can actually absorb into the blood.
Calcium Carbonate
Calcium carbonate contains 40 percent elemental calcium; the remainder is from the carbonate ingredient. Because calcium carbonate is more concentrated than other forms of calcium supplements, you need smaller doses to benefit from elemental calcium. Inexpensive antacids such as Tums contain calcium carbonate.
Supplements in the calcium carbonate form are best absorbed when ingested along with food because they require stomach acid to activate. In a study by Creighton University, Osteoporosis Research Center, Omaha, Dr. Robert Heaney and associates compared calcium sources and found that both calcium carbonate and calcium citrate supplements were equally well absorbed. However, there is a significant difference in cost and it was determined that supplementing with calcium carbonate to prevent fractures associated with osteoporosis would yield considerable net savings in U.S. annual health care costs, as published in the "Journal of the American College of Nutrition."
Calcium Citrate
Calcium citrate has 21 percent elemental calcium. This supplemental form of calcium does not require the presence of extra stomach acid to dissolve so it can be taken anytime, with or without food. Calcium citrate supplements may be a better choice if you are taking antacids or prescription medications. Available in a liquid form, calcium citrate may be less irritating to the stomach.
The "Journal of Clinical Pharmacology" reported a 2001 study by the Center for Mineral Metabolism and Clinical Research, University of Texas comparing bio-availability of supplements each containing 500 mg of elemental calcium. The conclusion was calcium in calcium citrate is better absorbed and available to the body than calcium carbonate when given with a meal. According to "Arthritis Today," supplementing with vitamin D increases calcium absorption by up to 65 percent.
Other Forms of Elemental Calcium
Calcium supplements are also available as calcium phosphate, calcium lactate and calcium gluconate. All of these forms have a small percentage of elemental calcium. Do not take calcium phosphate or antacids that contain calcium without talking with your doctor about possible interactions with any medications you may be taking. Many supplements contain unrefined oyster shell, bone meal or dolomite fillers that may contain high levels of lead or other toxic metals.
References
- NIH Osteoporosis and Related Bone Disease National Resource Center: Calcium Supplements: What to Look for
- Calcium Info: Best Forms of Calcium Supplementation
- The University of Arizona: Calcium Supplement Guidelines: What About Other Calcium Supplements?
- "Journal of the American College of Nutrition:" Absorbability and Cost Effectiveness in Calcium Supplementation; Robert P. Heaney, MD et al.; 2001
- PubMed: "Journal of Clinical Pharmacology:" Pharmacokinetic and Pharmacodynamic Comparison of Two Calcium Supplements in Postmenopausal Women; Heller HJ et al; 2000
- "Arthritis Today": Vitamin & Mineral Guide: Vitamin D: Research Note
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