Comparison of the effect of medium-chain and long-chain triacylglycerls on calcium absorption in healthy subjects

Background: The absorption efficiency of calcium in humans is low. Some studies in infants have shown that calcium absorption can be increased by adding medium-chain triacylglycerols to the formula diet. Objective: The effect of medium- and long-chain triacylglycerols on calcium absorption was studied in 18 healthy, young men. The results were compared with data obtained from calcium ingestion of a protein-carbohydrate formula devoid of triacylglycerols. Design: Calcium absorption was measured by using a double-isotope technique and the kinetic parameters were obtained by using a deconvolution method. Results: The total fractional calcium absorption measured in the presence of medium-chain triacylglycerols (0.236 +/- 0.016) or from a protein-carbohydrate formula without triacylglycerols (0.235 +/- 0.012) was not significantly different. The same result was observed with long-chain triacylglycerols (0.309 +/- 0.026) and the protein-carbohydrate formula (0.275 +/- 0.012). No kinetic parameters were significantly different regardless of the diet (protein-carbohydrate, medium-chain triacylglycerol, or long-chain triacylglycerol). This suggests that the same mechanism for calcium absorption was operative. Conclusions: Triacylglycerols had no direct effect on calcium absorption from a protein-carbohydrate formula in healthy subjects. These data do not support the use of medium-chain triacylglycerols as adjuvants to increase the absorption of calcium in healthy adults.