A xenobiotic is a chemical found in an organism that is not normally expected to be in that organism. Examples include drugs, pesticides, cosmetics, flavorings, fragrances, food additives, industrial chemicals and environmental pollutants. Humans are exposed to millions of xenobiotics in their lifetimes.
When your body absorbs drugs, pesticides, heavy metals or other potential toxins, what happens to them? How does your body get rid of these xenobiotics?
Most xenobiotics enter the body via the diet, air, drinking water, drug administration, and lifestyle choices. They then undergo a detoxification that in general renders them less toxic, and more readily excretable.
So how does your body rid itself of xenobiotics? Often through an enzyme called “CYP3A4 cytochrome P450.” CYP3A4 cytochrome P450 actually activates some drugs as well, turning them into their active metabolite, but it is mainly involved in cellular detoxification. Guess what, its gene is upregulated by vitamin D!
Thompson PD, Jurutka PW, Whitfield GK, Myskowski SM, Eichhorst KR, Dominguez CE, Haussler CA, Haussler MR. Liganded VDR induces CYP3A4 in small intestinal and colon cancer cells via DR3 and ER6 vitamin D responsive elements. Biochem Biophys Res Commun. 2002 Dec 20;299(5):730-8.
One possibility that is not in the literature is that vitamin D may shorten the effectiveness of many prescription drugs by hastening their removal from the body via inducing CYP3A4 cytochrome P450. If so, that may have major medical consequences, if it goes unrecognized, as it now is. In the future, drug doses may be titrated to 25(OH)D levels, knowing the higher the level the shorter the more the effect on time the drug will be in the body.
Unfortunately, medical literature lacks more studies or a review on the topic of late. A slightly more recent paper about the vitamin D receptor (VDR) mentioned it but only just barely, although as an aside, I like the “Fountain of Youth” conclusion of the authors.
“Clearly, through control of key genes, VDR indeed feeds the “Fountain of Youth” and allows one to age well by delaying fractures, ectopic calcification, oxidative damage, infections, autoimmunity, inflammation, pain, cardiovascular disease, and malignancy.”
Haussler MR, Haussler CA, Whitfield GK, Hsieh JC, Thompson PD, Barthel TK, Bartik L, Egan JB, Wu Y, Kubicek JL, Lowmiller CL, Moffet EW, Forster RE, Jurutka PW. The nuclear vitamin D receptor controls the expression of genes encoding factors which feed the “Fountain of Youth” to mediate healthful aging. J Steroid Biochem Mol Biol. 2010 Jul;121(1-2):88-97. Epub 2010 Mar 20.
So, what does this mean? As I have written before, vitamin D is the repair and maintenance man of the human body, repairing and maintaining cells and actually lengthening telomeres, shortened telomeres being the genetic markers of aging.
All steroids have their roles, testosterone in maleness, estrogen in femaleness, progesterone in pregnancy, etc. Cellular detoxification is but another repair and maintenance job of vitamin D, leading to healthy aging.