EFFECTS OF SUPPLEMENTAL DIETARY CALCIUM ON QUANTITATIVE AND QUALITATIVE FECAL FAT EXCRETION IN MAN

Oral calcium supplementation is thought to be a useful interventional agent to decrease colon cancer risk. This is supposedly due, at least in part, to the binding of bile acids and fatty acids by calcium in th e colon, thus prohibiting the damaging effects of these substances to the epithelium. To determine the effects of calcium supplementation on fecal fat excretion, 24 subjects kept a fat and calcium constant diet for one week and were supplemented with either 0, 2 or 4 g elemental calcium as calcium carbonate in a double-blind fashion. At the end of the week 72-hour feces was collected, and total fat, neutral fat, fatt y acids and the ratio of polyunsaturated and saturated fatty acids (P/ S ratio) were measured. Calcium dose-dependently increased the percent ual excretion of total fat as related to fat intake: 6.8 +/- 0.9% duri ng O g, 7.4 +/- 1.0% during 2 g and 10.2 +/- 1.4% during 4 g, r = 0.44 , p = 0.03. This was due to increased fatty acid excretion, excretion of neutral fat was not affected, nor was the P/S ratio. It is conclude d that calcium supplementation modestly increases fecal fatty acid exc retion. No adverse metabolic effects are to be expected from this in c ase of long-term calcium supplementation in subjects at increased risk for colon cancer.