The form of vitamin D most talked about is the one known as Vitamin D3 or
cholecalciferol, which is produced when the skin is exposed to sunshine.
Cholecalciferol is actually not a vitamin; it’s a prehormone which can be
metabolized into a secosteroid hormone called calcitriol. This hormone affects
over 2000 genes or 10 percent of the human genome. That is probably why this
"vitamin" affects the pathology of at least 17 varieties of cancer, as well as
heart disease, stroke, hypertension, autoimmune disease
, diabetes, depression, chronic pain, osteoarthritis, osteoporosis, muscle
weakness, muscle wasting, birth defects, and periodontal disease among others.

Vitamin D Deficiency

When we are talking about vitamin D deficiency, we need to know what form of
this vitamin we are referring to. The correct form is 25-hydroxyvitamin D.
That is why it’s a good idea to get a 25-hydroxyvitamin D test to determine
whether you are vitamin D deficient.

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According to Dr. John Cannell, president of vitamin D council, any serum level
of 25-hydroxyvitamin D lower than 50 mg per ml in both children and adults
should be considered vitamin D deficient. Many vitamin D experts recognize this
level as the minimal acceptable level. At this level or lower, vitamin D cannot
be stored in certain tissues of the body. In order to prevent many forms of
diseases, 25-hydroxyvitamin D in the blood should fall into the range between
50 and 80 mg per ml year around.

Vitamin D3

Vitamin D3 is a form of vitamin D, which is chemically called cholecalciferol.
When we use the name vitamin D3, we often want to distinguish it from vitamin
D2 or other forms of vitamin D.

Vitamin D Levels and Diseases

The status of your blood vitamin D3 or cholecalciferol can affect the risk for
all types of diseases such as autism, cancer, depression, mental illness, and
other ailments.

Although 50 mg per ml year round is considered adequate for healthy people, 75
mg per ml or higher levels may be needed to prevent cancer. Be aware that more
than 100 mg per ml may be too much for most people. Again we are talking about
25-hydroxyvitamin D.