MCHC

Calcium Citrate Shown to Have Superior Bioavailability

Calcium carbonate has been recommended by many doctors who are not informed on the latest research, with many patients taking Tums and other calcium carbonate sources. Carbonate forms require stomach acid to be absorbed, and many patients are hypochlorhydric (not enough stomach acid) and become more so with age. In addition, many calcium sources are coming under fire for containing heavy metals such as aluminum and lead. Calcium citrate and MCHC are probably the most optimal sources of calcium. And, don’t forget that calcium is not all that is needed for bone health; we need numerous other minerals and vitamins, which are not typically found in most calcium supplements.

J Clin Pharmacol. 2000;40:1237-1244 The study, published in the November issue of the Journal of Clinical Pharmacology, used 3 measures to determine calcium bioavailability — serum calcium, urinary calcium, and serum parathyroid hormone (PTH). This randomized crossover study compared the single-dose bioavailability and effects on PTH of commercial calcium citrate 250 mg (Citracal, Mission Pharmacal) and calcium carbonate 500 mg (Os-Cal, SmithKline Beecham) supplements in postmenopausal women. Dr. Heller continued, “calcium citrate produced greater suppression of serum PTH by more than 50% over calcium carbonate. This provides physiological evidence that calcium citrate was better absorbed. We additionally found that calcium citrate may be particularly advantageous in those who absorb calcium poorly from calcium carbonate. Our data suggests that there is an important difference in bioavailability between calcium supplements in postmenopausal women. Careful long-term studies should be done to determine if there is an equal difference in protection against bone loss and fracture.”