Zinc

What is it: Zinc is an essential mineral taken orally for several conditions including diabetes, hypertension, and BPH. Topically it improves wound healing. The daily requirement is 8 mg for women and 11 mg for men.

Mechanism of action: Zinc is required for T-lymphocyte development & activation. It may compete with rhinovirus for binding of ICAM-1 receptors, thus preventing cell invasion. Extracellular zinc ions reduce cell membrane permeability contributing to decreased viral penetration of cells and decreased edema. In-vitro studies show that zinc can prevent replication of the rhinovirus as well. It is also an antioxidant, thus preventing cell and tissue damage.

How to use it: Start taking zinc in the first 24 hours of cold symptoms. The dose is at least 13.3 mg of zinc gluconate orally every 2 hours while awake, taken until symptoms are gone. Newer nasal preparations (sprays or gels) are also effective, but may have more side effects (see below).

Results to expect: Fewer symptoms and less severe symptoms. The duration of the cold may be reduced by as much as one to three days.

Side effects: The most troublesome is the bad taste of zinc. Nausea is also reported. Nasal preparations produced headache, bad taste, epistaxis, and nasal tingling in both the zinc and placebo groups. There are anecdotal reports of anosmia with zinc nasal preparations.

Interactions: Chronic ingestion of 150 mg to 450 mg can lower copper levels unacceptably or interfere with iron function producing anemia.