Abstract Poultry are commonly fed diets based on corn and soybeans. Much of the phosphorus present in these feedstuffs is in the form of a phytate complex. Phytate phosphorus is relatively insoluble in the digestive tract of birds and mostly not absorbed. 1-α-hydroxycholecalciferol (1-α-OH-D3) and 25- hydroxycholecalciferol (25-OH-D3), both vitamin D metabolites, have been used to increase the utilization of phytate phosphorus, improve performance and bone mineralization, and decrease tibial dyschondroplasia. The present review aims to provide scientific information regarding the use of vitamin D3 metabolites such as 1 alpha-hydroxycholecalciferol and 25-hydroxycholecalciferol. Both of them are precursors for 25 (OH)2 D3, which is the metabolically active form of vitamin D3 in laying hens and broilers