Genetic selection in broilers focused on high growth rates is associated with an increase of leg disorders in commercial broilers. Bone health is determined by calcium and phosphorus metabolism through specific hormonal regulation pathways in kidney, jejunum, and liver. This study sought to define effects of genetic selection in mineral response mechanisms. Therefore, a comparison of calcium and phosphorus metabolism regulators in kidney, jejunum, and liver as well as bone mineral content during embryonic and early post-hatch development between Athens Canadian Random Bred (ACRB) and Cobb 500. Levels of mRNA of associated regulators and transporters were measured by RT-qPCR. Enzymatic conversion of vitamin D3 and hormonal regulation of calcium and phosphorus was found to be diminished in Cobb, which suggests that genetic selection has had an impact in regulation of calcium and phosphorus metabolism, leading to impairment in bone health and increased incidence of leg disorders in commercial broilers.