Zinc

What is zinc?

Zinc is an essential trace mineral found in cells throughout the body. According to MedlinePlus, it is needed for the immune system to work properly and plays a role in cell division, cell growth, wound healing and the breakdown of carbohydrates. Zinc is also needed for the senses of smell and taste, and it supports normal growth during pregnancy, infancy and childhood. It also enhances the action of insulin.

Good food sources include beef, pork, lamb, the dark meat of chicken, shellfish, nuts, whole grains, legumes and yeast. Zinc from animal foods is absorbed more easily than zinc from plants, so vegetarians and people on low-protein diets are more likely to run low.

What the research says

The clearest use of zinc supplements is for the common cold. MedlinePlus reports that, based on an expert review, zinc taken for at least five months may reduce the risk of catching a cold, and starting zinc within 24 hours of symptoms may shorten colds and make them less severe. MedlinePlus also notes that supplementing above the recommended intake is not generally recommended.

Zinc is sometimes marketed for ear health because it is present in the inner ear and is involved in nerve signaling. The best test of this idea is a Cochrane review on zinc supplementation for tinnitus. Pooling randomized controlled trials in adults, the reviewers found no evidence that oral zinc improves tinnitus symptoms, and they rated the evidence as low to very low quality.

We found no clinical trials showing that zinc supplements improve balance or steadiness in people who are not deficient. People with a true zinc deficiency may benefit from correcting it, but that requires a diagnosis.

We rate the evidence as limited for the uses Claritox Pro implies.

How it’s used in supplements

Zinc is found in most multivitamins and in stand-alone tablets, lozenges and immune formulas, often as zinc gluconate, sulfate, citrate or acetate. MedlinePlus notes it is not known whether one form is better than the others. Adults need about 8 to 11 mg a day, and the tolerable upper intake level for adults is 40 mg a day from all sources.

Large doses can cause diarrhea, abdominal cramps and vomiting, usually within hours of taking them. More importantly, MedlinePlus warns that long-term excess zinc intake can lead to copper, iron or magnesium deficiency. Copper deficiency can cause anemia and nerve problems, so taking high-dose zinc for months without medical advice is not a good idea. Zinc can also reduce absorption of certain antibiotics, so space doses apart from those medicines.

In Claritox Pro, zinc is listed without an amount, so we cannot tell whether it is a modest dose or a high one. If you already take a multivitamin, check your total zinc intake before adding another product that contains it.