Vitamin D: Two Dihydroxylated Metabolites Are Required for Normal Chicken Egg Hatchability

Abstract

When hens are raised to sexual maturity from hatching with 1,25-dihydroxyvitamin D 3 [1,25(OH) 2 D 3 ] as their sole source of cholecalciferol (vitamin D 3 ), fertile eggs appear to develop normally but fail to hatch. When hens receive a combination of 1,25(OH) 2 D 3 and 24R,25-dihydroxyvitamin D 3 [24,25(OH) 2 D 3 ], hatchability equivalent to that with hens given vitamin D 3 is obtained. These results suggest a biological role for 24,25(OH) 2 D 3 not previously recognized.