Zinc is an essential trace mineral, so you need to consume it in small amounts to stay healthy. Women age 19 years and older need 8 mg per day, and men age 19 years and older need 11 mg per day for an adequate intake, as determined by the Food and Nutrition Board. Because oral zinc supplements are generally not intended for long-term or high-dose use, consult a qualified health care provider before taking these supplements.
Tolerable Upper Intake Level
In addition to establishing the adequate intake for zinc, the Food and Nutrition Board also has set a tolerable upper intake level, or UL, of 34 mg for both males and females ages 14 to 18 years old and 40 mg for those of age 19 and older. Taking more than this increases the risk of negative effects. These limits do not apply if you take zinc for medical treatment, but you should do so only with the supervision of your doctor, says the Office of Dietary Supplements. In general, routine zinc supplementation is not advisable.
Acute Toxicity
Acute zinc toxicity may occur if you take high doses of oral supplements. Side effects may include loss of appetite, nausea, vomiting, diarrhea, abdominal pain or cramps, fatigue and headaches. Taking 150 to 450 mg per day has been connected with changes in iron function, decreased immune system function and decreased levels of high-density lipoprotein cholesterol, known as the good cholesterol, according to the Office of Dietary Supplements. Singles doses of 10 g or more can be fatal, according to the U.S. National Library of Medicine's MedlinePlus.
Chronic Toxicity
Chronic toxicity also can occur if you take oral zinc on a routine basis, particularly at high doses. Taking approximately 60 mg per day for up to 6 weeks has been associated with low copper levels. In one study, the results of taking 80 mg per day for an average of 6 years indicated that chronically high zinc supplementation has negative effects on the urinary system, according to the Office of Dietary Supplements. Taking oral zinc supplements on a long-term basis increases the risk of prostate cancer.
Drug Interactions
Zinc supplements also interact with several types of medications. For instance, zinc supplements can reduce the absorption and effectiveness of certain types of antibiotics, nonsteroidal anti-inflammatory drugs such as ibuprofen and penicillamine used to treat rheumatoid arthritis.
Member Comments