Zinc is important to the function of many enzymes and hormones. It is critical to immune function.
Iron, calcium supplements, alcohol, infections, and surgery may alter the absorption of zinc.
Zinc is a cofactor in a number of enzymatic reactions. It is important for protein and DNA synthesis, wound healing, bone structure, immune function, healthy prostate tissue, and skin oil gland function.
Oysters are a good source of zinc, but also red meat and other shellfish. Whilst high in whole grains, legumes, and nuts, it is not very absorbable from these sources.
Zinc deficiencies can show as skin changes, hair loss, recurrent infections, and diarrhoea. While severe zinc insufficiencies are rare, simple insufficiencies are common. The may show as sleep disturbances, slow wound healing, acne, psoriasis, dandruff, rheumatoid arthritis, reduced appetite, and inflammatory bowel disease.
Zinc has also shown to be deficient in non-insulin-dependent diabetics.
Zinc may help relieve the common cold.
Safety and toxicity
Zinc supplementation should be kept at 15 mg a day or below for general, chronic consumption. Short-term supplementation may be beneficial, but should be kept below 80 mg per day.
If safe levels are not adhered to, a copper deficiency anaemia may result, because zinc and copper compete for absorption. Too much zinc can result in a depressed immune function.
Toxic effects may include dizziness, vomiting, lethargy, and anaemia.
Functional medicine considerations
Smokers have lower zinc levels, and zinc may help protect against damage to blood vessel walls. If a patient has a history of recurrent infections, skin conditions, slow healing wounds, or disrupted inflammatory response, zinc status should be assessed.