Effect of 1,25-dihydroxyvitamin D sub(3) on calcium and magnesium absorption in the healthy human jejunum and ileum

In calcium deficiency states such as chronic renal failure, 1,25-dihydroxyvitamin D sub(3) increases calcium and magnesium absorption toward normal levels. In the present study, the ability of exogenous 1,25-dihydroxyvitamin D sub(3) to increase calcium and magnesium absorption above normal rates in healthy subjects was investigated. The studies demonstrate that in healthy persons, exogenous 1,25-dihydroxyvitamin D sub(3) increases calcium absorption in both the jejunum and the ileum, and increases magnesium absorption in the jejunum.