Effects of low phosphorus and low calcium diets on the production and metabolic clearance rates of 1,25-dihydroxycholecalciferol in pigs.


Severe dietary calcium (Ca) or phosphorus (P) deficiency leads to a similar degree of stimulation of plasma and intestinal 1,25-dihydroxycholecalciferol (calcitriol) levels and intestinal Ca absorption. In contrast, P depletion causes a much smaller increase in the renal 25-hydroxycholecalciferol-1-hydroxylase enzyme activity than does Ca depletion. To test… (More)