Seasonal variations of serum 1,25-dihydroxyvitamin D3 and alkaline phosphatase in relation to the antler formation in the fallow deer (Dama dama L.).

Serum 1,25-dihydroxyvitamin D3 and serum alkaline phosphatase increased several fold during the antler formation period in July. Both maxima were observed in the second half of the antler formation period, where the mineralization of the antler takes place. In contrast serum levels of calcium and 25-hydroxyvitamin D3 showed no alternation or seasonal variation.