Zinc is a mineral with the atomic number 30. It is called an “Essential trace element”. This is because very small amounts of zinc are necessary for human health. Since the the human body does not store excess zinc, it must be consumed regularly as part of the diet. Zinc is the second-most-abundant trace mineral in your body — after iron and is present in every cell throughout the body. Zinc is very important for different essential body functions and numerous aspects of cellular metabolism. Zinc is necessary for the activity of over 300 enzymes that aid in metabolism, digestion, nerve function and many other processes.
It helps the immune system fight off invading bacteria and viruses, as it’s critical for the development and function of immune cells and cell signaling. Zinc also prevents the immune cell damage by reducing the oxidative damage. The body also needs zinc for proteins and DNA (the genetic material in all cells) synthesis. During pregnancy, infancy, and childhood, the body needs zinc to grow and develop properly as zinc plays a crucial role in cell growth and division.
This mineral is also fundamental to skin health and helps wounds heal and plays critical roles in collagen synthesis. Zinc is important for proper senses of taste and smell. Because one of the enzymes crucial for proper taste and smell is dependent on this nutrient. Zinc decreases oxidative stress and reduces levels of certain inflammatory proteins in your body. Zinc also enhances the action of insulin and thereby helps in maintaining normal health . blood glucose levels. Other than these, Zinc is also important for treating normal colds and boosting eye health and is very crucial for the brain development in children.
As zinc is a trace element, it is required in very minute amounts. So the normal serum zinc level that needs to be maintained is 0.66 to 1.10 mcg/ml.
But the serum level of zinc exceeds the normal level, which leads to zinc overdose or zinc toxicity. Because there are many sources of zinc throughout the environment, exposure and toxicity are not uncommon. There are case reports of toxicity as a result of inhalation from occupational sources, overuse of dietary supplements, use of denture cream, ingestion of pennies secondary to PICA, and erroneously prepared TPN. Some of these cases did have fatal outcomes.
The recommended daily adult intake of zinc is 15 mg. Symptoms usually do not become evident until ingestions exceed approximately 1 to 2 g of zinc. Toxic exposures have occurred through the gastrointestinal, dermal, respiratory, and parenteral routes.
Nausea and vomiting are commonly reported side effects of zinc toxicity. Typically, stomach pain and diarrhea occur in conjunction with nausea and vomiting. Inhalational toxicity can vary in its severity depending on the specific compound involved, as well as the duration of exposure. For example, smoke bombs containing zinc chloride can cause chest pain, airway irritation, and even an acute respiratory distress syndrome (ARDS)-like clinical picture with pulmonary fibrosis as long-term sequelae. (Agnew & Slesinger, 2021)
Symptoms of Zinc Toxicity
Less common, gut irritation and gastrointestinal bleeding have also been reported due to zinc toxicity. Furthermore, concentrations of zinc chloride (in form of zinc supplementation) greater than 20% are known to cause extensive corrosive damage to the gastrointestinal tract.
Taking more zinc than the established limit may cause flu like symptoms, such as fever, chills, cough, headache and fatigue. Intakes of 150–450 mg of zinc per day have been associated with such chronic effects as low copper status, altered iron function, reduced immune function, and reduced levels of high-density lipoproteins (Zinc – Health Professional Fact Sheet, n.d.). High levels of zinc also have negative effects on lipid composition of the human body. zinc
toxicity may lower your “good” HDL levels and not have any effect on your “bad” LDL cholesterol. This may increase the chances of heart diseases. zinc in excess of the recommended levels may also cause taste alterations, including a bad or metallic taste in your mouth. Although zinc plays an important role in immune system function, too much zinc can suppress your immune response.
When the serum Zinc level decreases than the normal level, that may lead to zinc deficiency. It is usually due to inadequate zinc intake or absorption, increased losses of zinc from the body, or increased requirements for zinc.
Symptoms of Zinc Deficiency
Most common symptoms of zinc deficiency are unexplained weight loss, wounds that won’t heal, lack of alertness, decreased sense of smell and taste, diarrhea, loss of appetite, open sores on the skin, delayed sexual maturity, excessive hair fall. If you’re pregnant and have zinc deficiency, your baby might not have what it needs to develop properly in your womb as zinc is extremely important for cell division and cell growth.
Zinc poisoning and deficiency both are potentially life threatening. Therefore, it’s important to seek medical help right away. To treat zinc deficiency, dietary inclusion of zinc rich food is important. If needed, zinc supplements can be taken. But, Do not self-prescribe the supplements, always consult a health-care expert to prevent zinc overdose.
Food sources of zinc are:
chickpeas, nuts, Oysters, mushroom, beef, fish, milk, seeds, kidney beans, poultry, cheese, peas, spinach etc.
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Hussain, W., Mumtaz, A., Yasmeen, F., Khan, S. Q., & Butt, T. (2014). Reference range of zinc in adult population (20-29 years) of Lahore, Pakistan. Pakistan journal of medical sciences, 30(3), 545–548.
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