Vitamin D's Cancer Prevention Explained
(New York, Reuters Health, 5/16/02)

Dr. David J. Mangelsdorf of the Howard Hughes Medical Institute at the University of Texas Southwestern Medical Center in Dallas, reports that he and his colleagues have an explanation for Vitamin D's apparent ability to prevent colon cancer. He explains that after the liver empties bile into the intestines to break down fatty foods, it then reabsorbs most of the bile acids, except for LCA which is detoxified by an acid-neutralizing enzyme called CYP3A. He speculates that, if the body is overwhelmed by the consumption of excessive fatty foods, CYP3A may be depleted, leaving LCA in a carcinogenic state. Vitamin D can overcome the depletion by triggering an increase in the expression of the gene for the CYP3A.