Zinc is supplied by oysters, whole grains, legumes, nuts, and meats. The recommended intake is 15 mg/day for men and 12 mg/ day for women. Pregnancy only increases the need 3 mg/day, and early and late lactation increases the needs to 7 mg/day and 4 mg/day, respectively, to avoid deficiency signs of slow growth, impaired taste and smell, poor wound healing, and skin problems.
Others at risk include alcoholic and individuals on long-term low-calorie diets. It takes 3 to 24 weeks for symptoms to appear, but supplementation relieves deficiency symptoms in a matter of days. To avoid an overdose, characterized by gastrointestinal upset, nausea, and bleeding, eating habits should be checked for zinc antagonists, for example, an excessive intake of fiber or iron.