Diet

The animals received either a vitamin D‐free diet (catalog number 960074; MP Biomedicals, Irvine, CA) or a standard vitamin D (control) diet (catalog number 960226; MP Biomedicals). The composition of the standard diet is as follows: vitamin‐free casein (13.0%); whole wheat flour (75.0%); corn oil (3.0%); alphacel, nonnutritive bulk (5.0%); calcium carbonate (0.8%); vitamin D (5 IU/g of diet); and calcium phosphorous‐free salt mixture (2.0%). The vitamin D‐free diet has the same composition as the standard diet except that it does not contain vitamin D. We have previously shown that receiving a vitamin D‐free diet for 30 and 90 days can decrease the serum levels of vitamin D (Goncalves et al. 2014; de Braganca et al. 2015).