1,25(OH)2D3 increases intracellular Ca2+. Percoll-purified sperm washed spermatozoa were incubated in the unsupplemented Earle's medium for 30 min at 37°C and 5% CO2, in the absence (NC) or in the presence of increasing 1,25(OH)2D3 concentrations (0.01 nM, 0.1 nM, 1 nM and 10 nM) or with 0.1 nM 1,25(OH)2D3 combined with anti-VDR Ab (AbVDR). Other samples were incubated in capacitating medium (Cap). Intracellular calcium was measured as reported in Materials and Methods. The calcium assay presented are representative examples of experiments that were performed at least seven times with repetitive results. Columns represent mean ± S.D. *P < 0.05 versus control, **P < 0.02, ***P < 0.01 versus control.