Can also be referred to as calciferol

There a few types or variations 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 calcification 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