Taking zinc for a cold? 4 Potential Side Effects to Know About First

Zinc is a mineral found in foods and taken as a supplement. This can help relieve cold symptoms and diarrhea. Zinc is available in a variety of products, including orally (by mouth) and topical (applied to the skin). Possible side effects of zinc supplements include gastrointestinal (GI) side effects, headache, dizziness, numbness, weakness, and abnormal levels in blood tests.

Doses of zinc greater than 1 to 2 grams may increase the risk of unwanted side effects.

Large doses of zinc can cause digestive side effects such as abdominal cramps, nausea, vomiting and diarrhea. These side effects are likely to occur within three to ten hours after ingesting a zinc supplement. Zinc can affect the bacteria and environment (microbiome) of the gut, increasing the risk of gastrointestinal side effects.

In one study, 84% of women and 18% of men reported nausea, abdominal cramps, and loss of appetite after taking 50 milligrams of elemental zinc three times daily for six weeks. The difference between women and men may be due to the fact that women weigh less on average than men.

Zinc can also cause diarrhea, although this mineral is sometimes used to treat diarrhea. One study found that zinc increases the risk of diarrhea in children taking high doses of zinc. However, other studies have found no difference in diarrhea risk. The risk of diarrhea is also higher when taking zinc with an iron supplement.

High doses of zinc may cause headaches or dizziness. These symptoms are more common after taking a high dose of zinc. If you use zinc as prescribed, the risk of problems is low.

Reducing your zinc dose and overall intake should help resolve these symptoms.

High doses of zinc can cause neurological (brain and nerve) problems, such as numbness and weakness. This is seen in people chronically exposed to high doses of zinc.

Some research suggests this could be due to low copper levels. Low copper causes weakness by reducing energy production and impairing iron and healthy blood cells throughout the body. This prevents your body from sending enough oxygen to your muscle tissues, which can lead to weakness.

These side effects are rare. If you begin to experience numbness or weakness, consult a healthcare professional immediately.

Excessive zinc consumption can affect iron, copper, and cholesterol levels in your body. When your body absorbs zinc, it binds to a protein that affects minerals (like copper and iron) in your body. With high levels of zinc, your body produces more of these proteins to get rid of the extra zinc. However, this then reduces the availability of minerals like copper and iron.

Low copper levels can cause anemia (low red blood cell count), high cholesterol, increased risk of infection, and bone diseases like osteoporosis.

To avoid any zinc-related side effects, do not take more than the recommended dose of zinc. The recommended dietary allowance (RDA) for zinc is as follows:

• Adult men: 11 milligrams
• Adult women: 8 milligrams
• Pregnant people: 11 milligrams
• People who are breastfeeding: 12 milligrams

The tolerable upper intake of zinc for adults is 40 milligrams.

If you notice gastrointestinal side effects when taking zinc, consider taking the supplement with food. However, absorption is generally better when taken on an empty stomach.

Talk to a healthcare professional if you have questions about zinc supplements and side effects.