title: Seasonal variation of vitamin D3 and 25-hydroxy vitamin D3 in human serum.
mesh_terms: D002762:Cholecalciferol / Q000097:blood* / Q000528:radiation effects; D005260:Female; D006801:Humans; D006887:Hydroxycholecalciferols / Q000097:blood* / Q000528:radiation effects; D008297:Male; D012621:Seasons; D014466:Ultraviolet Rays
chemical_list: D006887:Hydroxycholecalciferols; D002762:Cholecalciferol