Excess zinc is toxic. Too much zinc will interfere with the metabolism of other minerals in the body, particularly iron and copper. Symptoms of zinc toxicity occur after ingestion of 2gm of zinc or more.
Zinc toxicity, along with an induced copper deficiency, is becoming more of a problem as the routine and chronic use of large doses of zinc becomes more common. Those on long-term supplementation should be monitored for zinc and copper status.
One 17 year old male was found to have fatigue, hypocupremia, anemia, leukopenia, and neutropenia after 6 – 7 months using large daily doses of zinc for acne.
Signs, symptoms & indicators of Zinc Toxicity
Unexplained vomiting
Occasional/frequent unexplained fevers
Conditions that suggest Zinc Toxicity
Autoimmune Tendency
Prolonged large doses of zinc may, by lowering manganese levels, increase susceptibility to autoimmune reactions.
Manganese Requirement
An insidious effect of excess zinc over a period of years is the reduction of serum manganese, 90% of which is contained in the erythrocytes.
Risk factors for Zinc Toxicity
Major zinc supplementation
Long term administration of high doses of zinc require monitoring zinc status and should be consumed with small doses (2mg) of copper.
Absence of copper supplementation
Counter Indicators
(History of) copper supplementation
Recommendations for Zinc Toxicity
Test for Manganese Levels
Zinc causes a decrease in serum manganese levels.
Copper
Low doses of copper will help restore the imbalance between zinc and copper caused by long term excessive zinc intake.
Key
| Weak or unproven link |
| Strong or generally accepted link |
| Proven definite or direct link |
| Strongly counter-indicative |
| Highly recommended |
| Reasonably likely to cause problems |
Glossary
Zinc
An essential trace mineral. The functions of zinc are enzymatic. There are over 70 metalloenzymes known to require zinc for their functions. The main biochemicals in which zinc has been found to be necessary include: enzymes and enzymatic function, protein synthesis and carbohydrate metabolism. Zinc is a constituent of insulin and male reproductive fluid. Zinc is necessary for the proper metabolism of alcohol, to get rid of the lactic acid that builds up in working muscles and to transfer it to the lungs. Zinc is involved in the health of the immune system, assists vitamin A utilization and is involved in the formation of bone and teeth.
Metabolism
The chemical processes of living cells in which energy is produced in order to replace and repair tissues and maintain a healthy body. Responsible for the production of energy, biosynthesis of important substances, and degradation of various compounds.
Mineral
Plays a vital role in regulating many body functions. They act as catalysts in nerve response, muscle contraction and the metabolism of nutrients in foods. They regulate electrolyte balance and hormonal production, and they strengthen skeletal structures.
Iron
An essential mineral. Prevents anemia: as a constituent of hemoglobin, transports oxygen throughout the body. Virtually all of the oxygen used by cells in the life process are brought to the cells by the hemoglobin of red blood cells. Iron is a small but most vital, component of the hemoglobin in 20,000 billion red blood cells, of which 115 million are formed every minute. Heme iron (from meat) is absorbed 10 times more readily than the ferrous or ferric form.
Copper
An essential mineral that is a component of several important enzymes in the body and is essential to good health. Copper is found in all body tissues. Copper deficiency leads to a variety of abnormalities, including anemia, skeletal defects, degeneration of the nervous system, reproductive failure, pronounced cardiovascular lesions, elevated blood cholesterol, impaired immunity and defects in the pigmentation and structure of hair. Copper is involved in iron incorporation into hemoglobin. It is also involved with vitamin C in the formation of collagen and the proper functioning in central nervous system. More than a dozen enzymes have been found to contain copper. The best studied are superoxide dismutase (SOD), cytochrome C oxidase, catalase, dopamine hydroxylase, uricase, tryptophan dioxygenase, lecithinase and other monoamine and diamine oxidases.
Gram
(gm): A metric unit of weight, there being approximately 28 grams in one ounce.
Chronic
Usually Chronic illness: Illness extending over a long period of time.
Anemia
A condition resulting from an unusually low number of red blood cells or too little hemoglobin in the red blood cells. The most common type is iron-deficiency anemia in which the red blood cells are reduced in size and number, and hemoglobin levels are low. Clinical symptoms include shortness of breath, lethargy and heart palpitations.
Leukopenia
A condition in which the number of white blood cells circulating in the blood is abnormally low.
Acne
A chronic skin disorder due to inflammation of hair follicles and sebaceous glands (secretion glands in the skin).
Nausea
Symptoms resulting from an inclination to vomit.
Manganese
An essential mineral found in trace amounts in tissues of the body. Adults normally contain an average of 10 to 20mg of manganese in their bodies, most of which is contained in bone, the liver and the kidneys. Manganese is essential to several critical enzymes necessary for energy production, bone and blood formation, nerve function and protein metabolism. It is involved in the metabolism of fats and glucose, the production of cholesterol and it allows the body to use thiamine and Vitamin E. It is also involved in the building and degrading of proteins and nucleic acid, biogenic amine metabolism, which involves the transmitting of nerve impulses.
Autoimmune Disease
One of a large group of diseases in which the immune system turns against the body's own cells, tissues and organs, leading to chronic and often deadly conditions. Examples include multiple sclerosis, rheumatoid arthritis, systemic lupus, Bright's disease and diabetes.
Insidious
A symptom or condition of gradual onset or development.
Serum
The cell-free fluid of the bloodstream. It appears in a test tube after the blood clots and is often used in expressions relating to the levels of certain compounds in the blood stream.
Milligram
(mg): 1/1,000 of a gram by weight.