We are all paying much more attention to supplements now. Many of them are hard to overdose with, however some that we need can be bad news if we take too much. Zinc is an essential mineral that is needed by your body to manufacture about 300 enzymes. Each of these enzymes have diverse processes and functions such as cell reproduction, immunity, protein synthesis, wound repair, vision, protection and immunity. The immune system does not work as well when a person does not take in enough zinc. 

Some Zinc deficiency symptoms are diarrhea, lesions, loss of appetite, growth retardation (in children), hair loss, delays in wound healing, taste abnormalities.  Extra zinc  may help with the loss of taste sensation or smell, wound healing, anorexia / loss of appetite, paranoia, depression, strong body odor, impotence, certain hair, nail and  joint / arthritic problems, impotence, cataracts and optic neuritis, and some skin conditions such as acne and dermatitis.

The RDA of zinc is about 9-11 milligrams is enough for adults. However, only about 30% of the zinc that you intake can get absorbed by your body. Many factors can interfere with zinc absorption such as phytates in your brain and fibers. If your body cannot absorb as much as it needs, you may need to take zinc supplements in order to prevent a zinc deficiency. It has been shown to be effective  in shortening cold symptoms, reduce the severity of cold sores, increase energy levels, treat ADHD in children, fighting hair loss and managing conditions such as hypoglycemia and diabetes. 

There is not a reliable laboratory test that can exactly measure how much zinc your body needs.

TOO MUCH ZINC: Can lead to serious effects. A zinc dose of 40 milligrams is approved safe to use by FDA and a zinc dosage more than this can pose certain risks. In terms of zinc toxicity, there is no other way to put it: excess zinc is dangerous! It can interfere with the metabolism and absorption of other essential minerals in your body, most especially iron, magnesium and copper. Zinc side effects can become potentially serious if you take doses from 150 to 450 mg a day. Taking this much can decrease your copper, iron and magnesium levels, selenium, phosphorus, Vitamin A, B1, C, reduce your body's immune function, and reduce your HDL (good cholesterol) level.  It may also cause, or contribute to gastrointestinal problems, hair loss, anemia, loss of libido, impotence, prostatitis, ovarian cysts, menstrual problems, depressed immune functions, muscle spasms, renal tubular necrosis /interstitial nephritis, dizziness, vomiting, High zinc doses over long periods may increase the risk of urinary tract problems, including infections. An adult should not take in more than 40 to 70 milligrams of zinc per day from foods and supplements combined.

Rare side effects have also been reported and these include fever, sore throat, mouth sores, weakness and fatigue but you only need to take just enough. An overdose of zinc can lead to severe nausea and vomiting, headache, and fatigue.  

Zinc can reduce the body's ability to absorb some antibiotics and other drugs, which can cause them to not work well.