Vitamin D is a fat soluble vitamin found in some foods and is also produced from within the body when ultraviolet (UV) rays from sunlight strikes the skin. It works together with calcium, magnesium, and phosphate to carry out different reactions within the body. It assists in the absorption of calcium to help promote strong bones. Muscles need vitamin D to move and recent studies have show that muscle pain is a symptom of too little vitamin D. It is has been shown to help with the growth and survival of neurons (nerve cells).
The hot topic for vitamin D today is its role in the immune system. It inhibits B cell proliferation and suppresses the rapid production of T17 cells, which are inflammatory. These effects result in decreased production of inflammatory cytokines. Low and deficient vitamin D levels are also present in autoimmunity.
Signs of a vitamin D deficiency are frequent infections, muscle cramps, muscle aches, fatigue, depression, and bone pain,
Foods high in vitamin D are fatty fish and milk.