It seems to be ridiculous to promote antacid use a Calcium supplement, as so many M.D.s do, and in fact I inform my patients of the discrepancy. Disintegration is important because a tablet must disintegrate before it can be absorbed. Since calcium absorption is most rapid in the upper small intestine, a significant delay in the release of Calcium from a poorly disintegrating supplement will reduce the amount of Calcium absorbed. In studies testing the disintegration of calcium tablets, a single tablet is placed in an erlenmeyer flask containing 150 ml vinegar at room temperature and swirled vigorously every 5 minutes until disintegration is observed. The test is repeated four times per brand of tablet.
Patients can easily test their own brand of supplements at home using a similar procedure.
Postmenopausal women often suffer from achlorhydria which inhibits the absorption of calcium salts under fasting conditions. Comparison of in vitro and in vivo tests for determination of availability of calcium from calcium carbonate tablets. Disintegration time measured using USP criteria or with the vinegar test can be used to distinguish poorly available tablets from acceptable tablets. Consumer vinegar test for determining calcium disintegration. The mean disintegration times of various calcium products in vinegar ranged from 1.8 to greater than 30 minutes.