Vitamin D3 ("cholecalciferol") is produced by interaction of a very narrow spectrum of sunlight (Ultraviolet-B) with a certain type of cholesterol molecule in the skin. Vitamin D3 is formed naturally. Cholecalciferol in supplement form is identical to naturally-produced vitamin D3.
Vitamin D3 is converted by the liver to form a metabolite called "calcidiol", 25(OH)D ("25-hydroxy-vitaminD"), which circulates in the blood stream as "serum VitaminD". This is one's reservoir of vitamin D. The concentration of
calcidiol in the blood determines one's
true vitamin D status. Using Dr. Robert Heaney's terminology (see #143): "deficient" is any level less than 32 ng/ml, "sufficient" > 32 ng/ml. Six experts consider "
Optimal" levels between
50-100 ng/ml. There's been no toxicity reported in the medical literature below 200 ng/ml (see
#143). "Optimal" range is the target for fending off the incidence of disease, based on accumulated observational research (see #138 below). When seeking *TRUE* Vitamin D status, the level of calcidiol is what needs to be measured, i.e., the test for 25(OH)D ("25 hydroxy-vitaminD"). A large percentage of doctors ( >20% according to Drs. Cannell and Holick) still requisition the wrong test for vitamin D status; they incorrectly order the test for "calcitriol" levels. The test for "calcidiol" (25-hydroxy-D) is the correct one, is less expensive and is indicative of true status (refer to any of the research experts to confirm).
Kaiser Hospital began including the test for Vitamin D status as part of standard medical checkups for its health plan membership in 2009. One reason why Kaiser might have voluntarily invested in such testing (when other "health insurers" were seeking legislative exemption from reimbursing the test-cost to its subscribers unless already diagnosed as "deficient") could be the findings of the "Estimated benefit of increased Vitamin D status in reducing the economic burden of disease in W Europe". (See
#118 for the abstract of a study done for Western Europe which reports a 19-to-1 return on investment to test and supplement vitamin D status. The operational cost savings from the reduction of the incidence of a plethora of disease -- colon cancer, breast cancer, ovarian cancer, type 1 diabetes, multiple sclerosis, heart attack, Non-Hodgkins lmphoma, fractures, etc etc -- would be too great for any end-to-end medical service provider (such as Kaiser) to ignore, from a strictly business point of view. From a patient point of view, affirmation is given that Vitamin D testing and supplementation is, indeed, health promoting and disease-preventative with little cost burden.)
There can be differences in medical opinion over what is considered "normal" vitamin D status, but -- based on newest research after 1997, when 97% of what is now known about Vitamin D has been discovered --
any level of 25(OH)D
BELOW 32 ng/ml (80 nmol/L) is
"not adequate for any body system" (Heaney, see #138). This minimum-recommended concentration level of calcidiol -- 32 ng/ml -- is what's necessary to
optimize the regulation of calcium absorption through the digestive tract, necessary for brain, nerves and muscle tissue. While calcium absorption has long been recognized as the main role of Vitamin D, its fundamental stature with the human innate immune system was discovered only very recently (
2004-2005 and
2007 for the "definitive study" re cancer-risk reduction). Some (perhaps many) doctors consider 20 ng/ml "normal", but, if you view the chart in #138, you'll see that a level of "20 ng/ml" corresponds to the concentration necessary merely to prevent rickets, i.e., a "1997 reference frame".
(This is why it's always important in today's fast-changing medical environment re Vitamin D to know/confirm 1)
Which vitamin D test the doctor intends to requisition from the lab, 2) What is the specific
numeric value and units of the test result, and 3) Which
method of laboratory testing was used. A report of "normal" doesn't tell you anything about the reference frame used. Quest Lab's method was scandalously "way off" in the recent past, supposedly corrected, but see
Cannell*.)
Research since 1997 -- after the current standards for vitamin D were set -- now recognizes much higher levels of daily vitamin D for realization of the full benefits of Vitamin D's
active metabolite, calcitriol -- protection from (and, now...see #138, Dr. Donald L Trump, treatment of) disease and falls. Proposed new RDA standards for Vitamin D are > 10 times higher than current 400 IU/day. (See #143 for an
understanding of why there's no "one correct dosage" for everyone. The variables are many -- including, probably, how ill one is -- but Vitamin D is "very forgiving" (Heaney) and SAFE in the new range of dosages being proposed. Again, see #143 for links to video lectures of the medical research experts themselves.)
Serum Vitamin D, calcidiol ("25-hydroxy-D"), is processed by the Kidney (and other tissues
in situ), as needed to fight infection, cancers, autism, heart disease, etc. and converted to
active Vitamin D, "calcitriol", the "evolutionarily-oldest hormone...a seco-steroid with as many mechanisms of action as the 1,000 human genes it regulates”.
To keep up on the latest News and Research on Vitamin D, refer to the left-hand menu at Dr. John Cannell's website:
http://www.vitamindcouncil.org/. The newsletter archives is especially interesting to browse for the variety of topics covered. Dr. Cannell writes so non-medically trained readers can comprehend. He also responds to inquiries from readers.
Best wishes to you and yours.
P.S. Vitamin D supplementation deals with boosting of the human "Innate Immune System", while vaccinations -- CDC, NIH, AMA -- address only the "Adaptive Immune System". There's not a lot of money to be made in natural-occurring, unpatentable Vitamin D3, but there are big $$$-interests in promoting vaccines (and denigrating Vitamin D and/or its proponents). For interesting evidence re vaccine
ineffectiveness in the elderly and the "most likely" relevance of innate immunity, see the "ninth conundrum evident only recently...that epidemiological studies question vaccine effectiveness" in
On the Epidemiology of Influenza. In addition, the Opening Piece of the forum reveals the first "hard data" evidence that "vitamin D is incredibly protective against H1N1". You'll also see examples of attacks on the science and/or "promoters" of Vitamin D.
Myths, FAQ, "...Vitamin D: A Real Missing Link..." Prescription=D2 vs D3, Testing, Optimal Ranges#92
C. Garland: "The definitive study..." => "Vitamin D & calcium supplementation reduces cancer risk" (2007)
#138
Disease Incidence Prevention by Serum 25(OH)D Level --Cancers, Diabetes, MS, Fractures, HeartAttacks (Optimal Levels Plus a Chart]
#143
Safety & two MD's general recommendations: "How Much Vitamin D Should I Take?"* Dr. Cannell's
Vitamin D Theory of Autism was recently accepted by five
Harvard researchers. In a response to a mother of an autistic child, Cannell writes:
Finally, expect anger and defensiveness from many in the medical profession. Remember, if I'm right, it was not the evil power plants, or the mercury polluters, or the vaccine industry that caused your son's autism. It was the CDC, the NIH, the AMA, and all the other committees and organizations that fell for the dermatologists' calculations (the cosmetic industry will give me a larger grant if I warn about sunlight) and who then blasphemed the Sun God. That is, the worst charge you can level against medicine, "You have violated your primary duty; you have caused harm." If I am right, the current autism epidemic is the worst iatrogenic disease in human history.