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ditor’s note: The following article and tables were adapted from the author’s poster presentation at the 18th Annual Symposium on Advanced Wound Care and 15th Annual Medical Research Forum on Wound Repair in San Diego, Calif, April 21–24, 2005.
       For more than 20 years, clinicians have debated the role of zinc supplementation in wound healing. The effective therapeutic range or ideal biomarkers for zinc status remain uncertain. Adequate zinc stores are needed for wound healing, and some individuals are at risk for increased zinc losses and zinc deficiency. However, it is clear that prolonged high doses of zinc supplementation (100–450 mg/d) can cause adverse effects from chronic toxicity, such as impaired wound healing, decreased immune response, induced copper deficiency anemia, iron deficiency, headache, fever, chills, and fatigue. In some facilities, zinc supplementation with 220 mg (3 times a day) of ZnSO4, which provides 150 mg of zinc, has been given to “prevent” pressure ulcers. However, zinc supplementation has not been proven to prevent pressure ulcers, and this level of supplementation is rarely warranted.

Table 1

       Zinc supplementation (> 25 mg/d) can cause nausea, vomiting, metallic taste, and abdominal pain, but these side effects are fewer with effervescent tablets as compared to capsule form. As noted, excess zinc supplementation interferes with both copper and iron absorption, which may cause copper and/or iron deficiency. Excess copper intake can interfere with zinc absorption and cause zinc deficiency.
       On the other hand, zinc deficiency can result in suboptimal growth (a major issue in underdeveloped countries), delayed wound healing, decreased taste acuity, anorexia, hypogonadism (which can itself impair wound healing), skin and/or eye lesions, rash, night blindness, hair loss, and nail dystrophy. Drainage from a chronic nonhealing wound contains 8–10 times the number of matrix metalloproteases (MMP) than the drainage from a surgical/healing wound. All of these MMPs contain protein, and more than 200 of them contain zinc. Zinc is stored in various body tissues, but the epidermis contains 6–8 times more zinc than any other tissue. In these situations, it seems illogical to wait for the anticipated zinc deficiency to occur before supplementing with zinc. For many patients, encouraging foods high in zinc along with a daily multivitamin and mineral supplement may be both safe and effective.

Figure 1

However, in individuals with large and/or draining wounds, especially if other risk factors for zinc deficiency exist, some level of zinc supplementation seems warranted.
       As indicated in the zinc supplementation algorithm shown in Figure 1, the highest level of zinc supplementation (50 mg) is indicated for individuals with heavily draining wounds until the drainage stops. This is given in split doses in effervescent form for best tolerance along with 2 mg of copper per 25 mg of zinc to offset the risk of copper deficiency. For tube-fed clients with pressure ulcers, therapeutic formulas with higher levels of protein and micronutrients are used, and additional supplementation is not necessary.