Zinc
ZINC SUPPLEMENTATION
Your skin contains one fifth of your body's zinc supply. Rats and mice that are deficient in zinc develop a skin condition called keratogenesis that is very similar to human psoriasis (Hoffer and Walker, Orthomolecular Nutrition, p 156-157). Zinc deficiency in humans is the rule, not the exception. The US RDA for zinc is only 15 milligrams a day, and yet the average American takes in even less than that. (Williams, Nutrition and Diet Therapy, 7th ed., page 253) In spite of this, it is most uncommon to find either dietitians or doctors ever recommending a supplement of this mineral.
Research has shown that supplements of zinc are safe up to about 500 mg. daily. A more sensible daily dose of 50 mg to perhaps may be maintained for as long as is desired. A good multiple vitamin along with this will provide some balancing copper, as will (believe it or not) the copper water pipes in your home.
The "amino acid chelated" form of zinc ('chelated zinc') is better tolerated and better absorbed than zinc sulfate or other inorganic forms of the mineral.