Effect of Hypovitaminosis A and Supplementation of Vitamin D3 on Calcium and Oxalate Absorption by Rat Intestinal Brush-Border-Membrane Vesicles

Urolithiasis as a complication of gastrointestinal disorders is well recognized. Vitamin A deficiency is implicated as a possible etiological factor for stone formation and is known to affect the epithelia of the gastrointestinal, urogenital, and respiratory tracts. Therefore, the biochemical changes produced by vitamin-A deficiency on intestinal absorption of calcium and oxalate by brush-border-membrane vesicles (BBMV) was studied. The intestinal BBMV were prepared by differential centrifugation, and uptake of calcium and oxalate was studied by a rapid filtration technique (1).