Zinc is an important cofactor in numerous biochemical pathways including DNA and protein synthesis. It is essential for growth and functions as an antioxidant for cell membrane stabilization [7, pp. 151-157].
Absorption of zinc is dependent on age and content in the diet . Deficiency is related to impaired taste sensation, anorexia, impaired mental awareness, diarrhea, low testosterone, anemia, impaired wound healing, and alopecia . Because of the lack of laboratory testing to identify zinc deficiency, clinical assessment could include presence of white spots on the fingernails  and signs of immune dysfunction like frequent infections.
Supplementation using zinc sulfate 220 mg three times a day (equivalent to 50 mg elemental zinc) has been shown to be less bioavailable and not well tolerated. Other preparations like zinc citrate and picolinate are better tolerated.
Food sources include seafood, meats, wheat germ, dairy products, and egg yolk. To avoid deficiency, supplementation may be needed to improve interferon-gamma, interleukin 2, tumor necrosis factor and natural killer (NK) cell activity for improved immune function. Research from Dr. Bruce Ames, PhD, indicates that when cells fall short on any one of a handful of nutrients including zinc, severe genetic damages from mutations in the DNA and mitochondria occur . Zinc is an important trace mineral needing careful monitoring following bariatric surgery .