Also referred to as calciferol

There a few types of this vitamin

Is considered a fat soluble vitamin

1.)   D1  –  ergocalciferol + lumisterol

2.)   D2  –  ergocalciferol

3.)   D3  –  cholecalciferol

4.)   D4  -  22-dihydroegocalciferol

5.)   D5  –  sitocalciferol

Sources:

Skin

   -    Production of D3 occurs in the skin from 7-dehydrocholesterol and UV light from sunlight
   -    Some animals have very little vitamin D production in this manner
   -    Concentration of melanin is important

Foods

   -    Salmon
   -    Tuna
   -    Catfish
   -    Sardines
   -    Herring
   -    Fish oils
   -    Egg
   -    Beef liver

Function:

   -    Important role in health of many organ systems
   -    Helps the absorption of calcium and phosphorus
   -    Can promote calification of certain tissues
   -    Affects certain hormones
   -    Affects the Immune system
   -    others

Other health benefits

   -    Cancer prevention
   -    Improved immune system response
   -    Prevention of Cardiovascular Disease

Deficinecy

   -    Rickets
   -    Osteomalacia
   -    Osteoporosis
   -    confusion
   -    memory loss
   -    other risk factors for chronic diseases

Toxicity  –  is often rare
   -    Itching
   -    Excess urine
   -    Nausea
   -    Abdominal pain
   -    Possible renal failure