Calcium supplements: Practical considerations
The preferable source of calcium is a balanced diet, but medicinal supplements are sometimes necessary if patients are to reach desired intakes. A divided dose regimen (4×/d; i.e., with meals and at bedtime) results in substantially greater absorption of a supplement than does l×/d dosing. However, differences in chemical solubility between supplement preparations are of little importance, with calcium carbonate preparations, for example, being absorbed as well or better than some much more highly soluble salts. Gastric acid is not necessary for absorption of even poorly soluble preparations, so long as they are taken with meals. Because typical patients exhibit a wide range of absorption efficiencies, it is desirable to assess absorption fraction before beginning a supplement regimen. (Some patients will need three times as large a dose as others to absorb the same amount of calcium.) Calcium intakes up to at least 62.5 mmol (2500 mg) are safe for virtually all patients.
KeywordsCalcium absorption Bioavailability Calcium supplements Calcium compliance Calcium supplement dosage
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- 2.Heaney RP, Recker RR, Stegman MR, Moy AJ. Calcium absorption in women: relationships to calcium intake, estrogen status, and age. J Bone Min Res 1989; 4:469–75.Google Scholar
- 6.Carr CJ, Shangraw RF. Nutritional and pharmaceutical aspects of calcium supplementation. Am Pharmacy 1987; NS27:49–57.Google Scholar
- 7.Shangraw R. Factors to consider in the selection of a calcium supplement. Public Health Reports 1989; Sept–Oct: S46–50.Google Scholar
- 8.Heaney RP, Weaver CM, Fitzsimmons ML. The influence of calcium load on absorption fraction. J Bone Min Res 1990; 11:1135–8.Google Scholar
- 11.Horowitz M, Need AG, Philcox JC, Nordin BEC. Biochemical effects of a calcium supplement in osteoporotic postmenopausal women with normal absorption and malabsorption of calcium. Min Electrolye Metab 1987; 13:112–16.Google Scholar
- 13.Haynes RJ Jr, Murad F. Agents affecting calcification: calcium, parathyroid hormone, calcitonin, vitamin D, and other compounds. In: Gilman AG, Goodman LS, Rall TW, Murad F (eds) The pharmacological basis of therapeutics, 7th edn. New York: Macmillan, 1985:1517–22.Google Scholar
- 15.Heaney RP. Fecal calcium density: a measure of calcium compliance. J Bone Min Res 1990; (submitted for publication).Google Scholar
- 16.Heaney RP, Weaver CM, Fitzsimmons ML, Recker RR. Calcium absorptive consistency. J Bone Min Res 1990; 11:1139–42.Google Scholar
- 18.Heaney RP, Recker RR. Estimating true fractional calcium absorption. ‘Letter to the Editor’. Ann Intern Med 1988; 108:905–6.Google Scholar
- 23.Heaney RP. En recherche de la différence (P<.05). Bone Min 1986; 1:99–114.Google Scholar
- 26.Martin BR, Weaver CM, Smith DL. Calcium absorption from milk versus calcium carbonate in college-age women using stable isotopes. Fed Proc 1989; 3:A771 (abstract no. 3160).Google Scholar
- 27.Eastell R, Vieira NE, Yergey AL, Riggs BL. One-day test using stable isotopes to measure true fractional calcium absorption. J Bone Min Res 1989; 4:463–8.Google Scholar