Why Do We Need Vitamin D?

Vitamin D (Cholecalciferol, D3) is a fat soluble vitamin synthesized from cholesterol by the skin when it is exposed to ultra-violet B radiation (sun exposure). Once vitamin D is synthesized it is altered by the liver and kidney into its active form. Small amounts are obtained from dietary sources. Recent research points to a vitamin D deficiency epidemic in the U.S. Sunscreens (to include make-up) with an SPF of greater than 8 inhibit the synthesis of vitamin D. Not only is vitamin D necessary to maintain normal calcium levels, but it helps with the maintenance of the neuromuscular system and the immune system. In addition, vitamin D has genetic effects by regulating cell growth and differentiation. Some vitamin D deficiency associated diseases include rickets, osteomalacia, osteoporosis, and cancer.

Signs & Symptoms of Vitamin D deficiency:
Poor immune function
bow legs (softening or malformation of the bones)
Muscle pain
Muscle weakness
Poor growth
Skin lesions (eczema)
Acne

Vitamin D has been shown to be beneficial in the following conditions:
Cancer
High blood pressure
Type I and Type II Diabetes
Osteoporosis
Rickets
Osteomalacia
Autoimmune diseases

Drugs or additives that may deplete or interfere with Vitamin D metabolism:
Alcohol
Corticosteroids
Olestra (a food additive found in many fat free products)
Mineral oil (when taken consistently in higher doses)
Cholestyramine
Colesevelam (Welchol)
Colestipol
Statin medications – Although these medications have not been shown to directly decrease vitamin D levels in research studies, they inhibit cholesterol synthesis which could potentially effect vitamin D production.
Long term therapy with anti-convulsant medications is thought to interfere with the liver and kidneys ability to activate vitamin D.
Isoniazid and Rifampicin (Antibiotics) are also thought to interfere with the liver and kidneys ability to activate vitamin D.

Laboratory testing for Vitamin D:
25 OH-D
Lymphocyte proliferation assays

Vitamin D food Sources:
Liver, cod liver oil, herring, salmon, mackerel, sardines, tuna, eggs, and fortified dairy products.