Zinc is a type of nutrient that the body requires for metabolism, growth and development. Because the body does not create zinc, it must be obtained through your diet; but it is found in many foods. Zinc also helps to boost immunity; speeds wound healing and affects your sense of taste and smell. As with any vitamin or nutrient, too much zinc can adversely affect your health and cause significant physical symptoms.
Zinc is considered a trace element that is obtained through the diet and is added as a fortifier to many other foods. Zinc is found in seafood such as oysters, crab and lobster; dairy products, including cheese and milk; and grains, such as bran, oatmeal and fortified breakfast cereals. The recommended daily allowance of zinc for adults is 11 mg for men and 8 mg for women.
The American Cancer Society states that theories abound for taking zinc supplements, as zinc has been touted for treatment of various illnesses. Those who have low zinc levels may benefit from zinc supplements to help fight infection; and zinc supplements may help with sickle cell disease. Because of its promotional use, some people may take too many zinc supplements, which can lead to zinc toxicity.
An overdose of zinc can cause symptoms with long-term overuse of supplements. According to the National Institutes of Health Office of Dietary Supplements, signs of zinc toxicity include nausea, vomiting, diarrhea, abdominal pain and headache. Very high doses of zinc between 150 mg and 450 mg daily are associated with decreased immunity and lowered levels of HDL, the “good” cholesterol. The Office of Dietary Supplements does not cite problems with heart rate as being a symptom of zinc toxicity.
Long-term overdose of zinc can result in a deficiency of copper in the body, as high doses of zinc interfere with the body’s ability to absorb copper. According to Oregon State University’s Linus Pauling Institute, copper deficiency may be related to cardiovascular disease as a result of atherosclerosis, the hardening of the arteries due to fatty plaque deposits. Because zinc overdose can also lower levels of HDL cholesterol, LDL cholesterol may increase, causing atherosclerosis as well. Atherosclerosis can lead to a heart attack or peripheral artery disease, affecting your heart rate.
Contact your doctor if you notice an irregularity with your heart rate. If your heart is beating too fast, too slow or at an irregular rhythm, it can have difficulties maintaining blood flow to your organs and tissues. The Cleveland Clinic states that if your heart is beating irregularly, you may notice a feeling of pounding in your chest, dizziness, shortness of breath or weakness. Notify your doctor of your symptoms, how long you have had them, and what vitamins and supplements you are taking, including zinc.