Good Nutrition Nutrition

Nutrition Notes Topics

Zinc (Zn)

Zinc is a co-factor for at least 70 critical enzyme pathways. Deficiency can therefore result in diverse, profound problems; impaired synthesis of DNA, RNA, and protein underlie the clinical manifestations. Zinc deficiency may be more common than is diagnosed. The RDA for zinc is 5 mg/day for infants, 10 mg for children and 15 mg for adults. Zinc requirements increase in pregnant women to 20 mg/day.

Any child with growth retardation, poor hair growth, impaired immunity or skin problems should be considered for zinc deficiency, particularly if there are gastrointestinal absorption problems. Zinc absorption is impaired by phytates in cereal grains, and by the concurrent ingestion of other minerals, especially calcium, iron, cadium and copper. The best body zinc evaluation is the measurement of zinc concentrations in white blood cells. Hair zinc levels may be increased when zinc is markedly deficient.

Zinc deficiency produces: impaired senses of taste and smell, slow wound healing, white spots in the fingernails, night blindness (interacts with Vitamin A deficiency), low sperm count, hair loss, behavior or sleep problems; mental lethargy, impaired immune function, cyclic feeding and loss of appetite, dermatitis.

Zinc is depleted by the following drugs: Penicillamine, steroids, ethanol, diuretics, and oral contraceptives. Zinc is often promoted to "enhance immunity". It is an essential mineral for immune function. Perhaps because of its immune promoting role, deficiencies in zinc may be helpful in autoimmune diseases. Zinc concentrations are referred to copper, and the minerals tend to have a reciprocal relationship. A low tissue concentration of copper may result from zinc supplements. A suggested optimal zinc to copper ratio is 8:1.

Zinc Deficiency (ZD) promotes the development of various GI diseases through its negative effect on GI epithelial barrier function. ZD occurs with extensive use of Protein Pump Inhibitor drugs, diets with abundant phytate-rich foods, and decreasing consumption of meat and fish. Zinc supplementation has been shown to have a protective effect on the digestive tract epithelial barrier in animal models and humans in a variety of pathologies including chronic alcohol exposure, heat stress, diarrhea, CFS, colitis, other GI ailments, and even some neurological conditions. Often it can enhance the effects of other beneficial molecules, such as quercetin.