The keratinocytes of the skin are unique in being not only the primary source of vitamin D for the body, but in possessing the enzymatic machinery to metabolize vitamin D to its active metabolite 1,25(OH)2D.
Die keratinocytes van die vel is uniek in dat nie net die primêre bron van vitamien D vir die liggaam nie, maar in die besit van die ensiematiese masjinerie vitamien D metabolize sy aktiewe metaboliet 1,25 (OH) 2D.