Chelation of calcium by lactose: its role in transport mechanisms.

Lactose, like other sugars and polyols, prevents or delays the precipitation of calcium ion in the presence of bicarbonate buffer. That an uncharged calcium-lactose complex is formed was demonstrated by the use of paper electrophoresis and of calcium-45 as a label for the complex. Enhancement of the intestinal absorption of calcium ion by sugars could result from a complex of low molecular weight.