Posted by: Thixia | September 1, 2008

Vitamin D Pharmacology 2 of 2

A Prehormone


You will read that cholecalciferol is a hormone; it is not.  It is a prehormone.  In fact, it is no more of a hormone than cholesterol.  In a way it is similar to cholesterol.  For example, some of the cholesterol you eat is turned into hormones: estrogen, testosterone, progesterone, etc.  Some of the cholecalciferol from your skin or from supplements you take will be turned into hormones by the body.  So cholecalciferol is no more of a hormone than is cholesterol.


However, some of your cholecalciferol will be turned into calcitriol, a very potent steroid with anti-cancer properties.  Remember when I showed you how cholecalciferol is 10,000 times more potent than Tylenol?  Well calcitriol is 10,000,000,000 (ten billion) times more potent than Tylenol!  It is active in picogram quantities (1/1,000,000,000,000 of a gram)!





Another substance that is often called vitamin D is ergocalciferol (also referred to as vitamin D2 or Calciferol).  It is derived by radiating fungus.  It is not the naturally occurring vitamin D for humans.  Fungus contains fat-like substances called sterols which are commercially irradiated to form ergocalciferol.  As it is derived from plants, and not animals, ergocalciferol is considered Kosher.


Ergocalciferol is available to U.S.  doctors in prescription strength and is sometimes used in multivitamin preparations—usually at 400 IU per pill.  Your doctor can write a prescription for 50,000 units of ergocalciferol (brand names Drisdol and Calciferol).


Ergocalciferol does not exist in detectable quantities in the human body, only in tiny quantities in plants and as such is “unnatural”, when in the human body.  You can not get any appreciable ergocalciferol by eating vegetables.  Ergocalciferol is metabolized to various substances in the body, some of which are not normally present in humans, although these metabolites have never been shown to be dangerous.  There is also some evidence that ergocalciferol is more toxic in overdose, which is curious as it is only about half as potent as the naturally occurring vitamin D, cholecalciferol.  Your body also metabolizes ergocalciferol more quickly than cholecalciferol.



Vitamin D as a Prescription Medication


A number of the naturally occurring products of cholecalciferol metabolism are extremely potent and are only available as prescription medications.  They are also sometimes called vitamin D.  These include calcidiol (also sometimes called calcifediol with the brand names of Calderol and Dedrogyl), dihydrotachysterol (brand name DHT Intensol), and calcitriol (brand names are Rocaltrol and Calcijex when injected).



Vitamin D Analogues

Finally, a number of compuonds are based on variations of one of the naturally occurring vitamin D metabolites, usually calcitriol, and these are called vitamin D analogues.  They are frequently used in chronic renal disease when the kidney has lost the ability to make calcitriol.  The best known are doxercalciferol (taken orally with a brand name of Hectorol) and paricalcitol (intravenous with the brand name Zemplar).



Supplement With Cholecalciferol


The important thing to know: cholecalciferol is the vitamin D to take.  Do not let your doctor give you any prescription medication for vitamin D.  The only exception to this is ergocalciferol.  Although with ergocalciferol you must remember you are taking a drug—not a vitamin—that does not normally occur in the human body.




Compliments of:

Vitamin D Council


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