Bar, A., Institute of Animal Science, Agricultural Research Organization, The Volcani Center, P.O.B. 6, Bet Dagan, 50250, Israel
Rosenberg, J., Institute of Animal Science, Agricultural Research Organization, The Volcani Center, P.O.B. 6, Bet Dagan, 50250, Israel
Hurwitz, S., Institute of Animal Science, Agricultural Research Organization, The Volcani Center, P.O.B. 6, Bet Dagan, 50250, Israel

The contents of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) in plasma and intestinal mucose were increased by dietary calcium and by dietary phosphorus restriction. The concentration of intestinal occupied receptors for 1,25(OH)2D3 was higher in calcium-restricted birds. The affinity (association constant) of intestinal receptors for 1,25(OH)2D3 was lower in phosphorus-restricted chicks, as compared to control or calcium-restricted chicks. The number of binding sites were not influenced by dietary calcium or phosphorus restriction. © 1983.