1,25-Dihydroxyvitamin D₃ induces nerve growth factor, promotes neurite outgrowth and inhibits mitosis in embryonic rat hippocampal neurons

There is an accumulation of evidence implicating a role for vitamin D₃ in the developing brain. The receptor for this seco-steroid is expressed in both neurons and glial cells, it induces nerve growth factor (NGF) and it is a potent inhibitor of mitosis and promoter of differentiation in numerous cells. We have therefore assessed the direct effect of vitamin D₃ on mitosis, neurite outgrowth, as well as NGF production as a possible mediator of those effects, in developing neurons. Using cultured embryonic hippocampal cells and explants we found the addition of vitamin D₃ significantly decreases the percentage of cultured hippocampal cells undergoing mitosis in conjunction with increases in both neurite outgrowth and NGF production. The role of vitamin D₃ during brain development warrants closer scrutiny.