Vitamin D is a Hormone and not a vitamin
justification
calcitriol(1,25-DHCC) is now considers as an important calciotropic hormone, while cholecalciferol is the prohormone . The following characterstics features of vitamin D justify its status as a hormone
1.Vitamin D3(chalecalciferol) is synthesized in the skin by ultra-voilet rays of sunlite.
2.The biologically active form of vitamin D calcitriol is produce in the kidney.
3.Calcitriol action is similar to steroid hormone. It bindes to a recepter in the cytosole and the complex acts on DNA to stimulate the synthesis of calcium binding protein.
4.Calcitriol has target organs- intestine,bone and kidney,where it specifically acts.
5. Actinomycin D inhibits the action of calcitriol.this supports the view that calcitriol exerts its effect on DNAleading to the synthesis of RNA .
6.Calcitriol synthesis is self regulated by a feedback mechanism ie. calcitriol decreases its own synthesis
justification
calcitriol(1,25-DHCC) is now considers as an important calciotropic hormone, while cholecalciferol is the prohormone . The following characterstics features of vitamin D justify its status as a hormone
1.Vitamin D3(chalecalciferol) is synthesized in the skin by ultra-voilet rays of sunlite.
2.The biologically active form of vitamin D calcitriol is produce in the kidney.
3.Calcitriol action is similar to steroid hormone. It bindes to a recepter in the cytosole and the complex acts on DNA to stimulate the synthesis of calcium binding protein.
4.Calcitriol has target organs- intestine,bone and kidney,where it specifically acts.
5. Actinomycin D inhibits the action of calcitriol.this supports the view that calcitriol exerts its effect on DNAleading to the synthesis of RNA .
