Vitamin D and You

Vitamin D and You   pdf download 
What is Vitamin D?
Vitamin D is a fat-soluble vitamin produced in the body when ultraviolet rays from sunlight  strike the skin. At least 75 per cent of the body’s supply comes from conversion of 7-dehydro-cholesterol in the skin. This molecule is then converted in the liver to 25-OH vitamin D3, the major form circulating in the blood.  Functioning as an endocrine gland, the kidneys  further process 25-OH vitamin D3 to its active metabolite, 1α,25-OH-D3. Receptors for this hormone-like substance are present in nearly every organ. Lack of exposure to sunlight is the main cause of vitamin D deficiency.
Why should I be tested?
Everyone, from infants to seniors, need to be tested regularly. Serum (blood) concentrations reflect the amount of vitamin D produced through the skin and obtained through foods and supplements. There is no way to know for certain if you have adequate levels without a test. The minimal acceptable therapeutic level for both children and adutls is 50 ng/mL. Below that level, the body uses vitamin D as quickly as it is made; above that level, vitamin D can be stored for future use. The optimal range is between 50 and 80ng/mL year round. Levels greater than 200ng/mL are considered toxic.*
*Blood tests for 25-OH vitamin D are reported in both nanograms per milliliter (ng/mL) and nanomoles per liter (nmol/L).  Ex: 1 ng/mL = 2.5 nmol/L   Ex: 32ng/mL = 80nmol/L