Zinc Picolinate: Absorption and Supplementation

There is concern regarding the absorption of zinc, both from dietary intake and nutritional supplements, because of zinc’s essential role in human nutrition and metabolism, and because of evidence that some population groups have a marginal to deficient intake of zinc. While oral zinc supplementation is efficacious in most zinc deficiency conditions, not all zinc preparations have equal bioavailability. Acrodermatitis enteropathica (AE), a rare genetic disorder characterized by a severe zinc deficit, provides an excellent model for understanding zinc deficiency and absorption in humans. Patients with AE have a defect in tryptophan metabolism which may predispose them to producing decreased levels of picolinic acid (PA). PA, a natural product of normal tryptophan metabolism in the body, has been shown to be an important, if not essential component of zinc absorption. Zinc picolinate appears to have the greatest efficacy in reversing the zinc deficiency of AE and is also absorbed to a higher degree in normal subjects than other zinc supplements. Unlike supplementation with many other mineral chelates, use of exogenous zinc picolinate may actually provide the compound normally created by the body in the intestinal tract to facilitate absorption. (Alt Med Rev 1996;1:26-30.)