An adult’s body contains only 2-3 grams of zinc and the role of this mineral for the normal functioning of the body can not be underestimated. Zinc is essential for the proper functioning of the immune system and wound healing, participates in the processes of cell division and growth, enhances the action of insulin and is essential for normal odor and taste.
During pregnancy, infancy and childhood, zinc is essential for the growth and normal development of the child.
What is zinc?
Zinc is a vital trace element for humans, which is involved in the work of more than 300 enzymes (compounds that accelerate processes in the body) and 1000 transcription factors (proteins involved in RNA synthesis).
The importance of zinc for the human body was demonstrated in 1961, when in many clinical cases it was found that zinc deficiency in the diet leads to anemia (decrease in hemoglobin and red blood cells), hypogonadism (decrease in the level of sex hormones) and . Subsequent dietary adjustments with zinc supplements and additional studies have confirmed a direct link between zinc deficiency in the body and health problems.
Zinc is naturally present in some foods, but is also available as a supplement.
The role of zinc in the immune system
Zinc is essential for the normal functioning of the immune system. People with zinc deficiency are more susceptible to microorganisms – viruses, bacteria, fungi.
Zinc affects many aspects of the immune system:
- the formation and function of a lipid barrier on the surface of the skin, protecting it from bacteria, viruses, fungi.
- growth and function of non-specific (innate) immune cells – neutrophils and natural killers (NK-cells).
- T-cell activation (acquired immune cells).
- the function of macrophages – cells in the body that capture and assimilate particles foreign to the body, dead cells, bacteria and viruses.
- Zinc acts as an antioxidant.
The role of zinc in a woman’s body
Adequate zinc intake is essential for the maturation of the eggs, the proper formation and development of the fetus during pregnancy and the normal development of the child during breastfeeding.
The role of zinc in a man’s body
Zinc is essential for testosterone synthesis, prostate function, sperm production and is essential for male fertility. The concentration of zinc in the blood can be considered as one of the indicators in the prevention, diagnosis and treatment of male infertility.
It also acts as an antibacterial agent in the urinary system.
Digestion by the body
After ingestion, zinc is absorbed in the small intestine. Aqueous solutions are best absorbed on an empty stomach: for them, the absorption (the efficiency with which the tissues absorb elements) is 60-70%. For solid foods, this percentage is lower (about 33% on average), although it may vary depending on the diet and the zinc content of the food.
Also, the absorption of zinc is affected by the current level of the micronutrient in the body. People with severe deficiency absorb zinc more efficiently than those with normal blood counts.
The rule of zinc in the body
The average concentration of zinc in the blood serum is 700-1500 micrograms per liter. The variation is influenced by the sex, age and collection time of the sample, which must be taken into account if you donate blood to detect a possible defect.
Maintaining adequate levels of zinc in the body is important for survival, so in addition to being taken in and absorbed from food, there is also an internal excretion of zinc in the intestines, which allows the excretion of excess along with the stool. The processes of food absorption and internal excretion are interrelated and regulated by the body according to the level of zinc intake from food and supplements.
The recommended doses for healthy people are:
- infants 0–6 months, 2 mg / day.
- infants 7–12 months and children under 3 years, 3 mg / day.
- children 4-8 years – 5 mg / day.
- children 9-13 years – 8 mg / day.
- young 14-18 years and adult men – 11 mg / day.
- girls 14-18 years – 9 mg / day.
- adult women – 8 mg / day.
- pregnant women – 11 mg / day.
- breastfeeding women – 12 mg / day.
For pregnant and lactating women, it is necessary to increase the intake of zinc, as part of it leaves the mother’s body for the development of the fetus and breast milk. However, due to the potential risk of various substances and deficiencies for the fetus and newborn, in these cases, consultation with a specialist is mandatory.
Zinc deficiency in the body
Symptoms of deficiency:
- Violation of physical growth and development during the fetal period, in infants and during adolescence, when the need for zinc is high.
- infections – pneumonia, malaria, bacterial or viral diarrhea (possibly due to disorders of the immune system and intestinal mucosa).
- Early signs of aging – disorders of the immune system, delayed wound healing.
- cognitive impairment, behavioral problems, memory impairment, learning difficulties.
- skin problems, hair loss;
- vision problems?
- weight loss;
- taste disorders.
Many of the symptoms are non-specific and may be related to other medical conditions, so a medical examination, including a blood test, is necessary to confirm zinc deficiency.
The reasons for the insufficiency can be:
- a diet low in zinc;
- Enteropathic acrodermatitis – an inherited metabolic disorder that leads to zinc deficiency in the body.
- malabsorption syndrome – a chronic disease due to which food is not well digested and the absorption of necessary elements in the intestine is disturbed.
- infectious diseases.
The risk group includes:
- people with gastrointestinal disorders, which may reduce the absorption and increase the loss of zinc from the gastrointestinal tract.
- people with chronic liver disease, kidney disease.
- Vegetarians: do not eat meat rich in bioavailable zinc, but consume large amounts of legumes and whole grains that contain phytic acid, which binds zinc and prevents its normal absorption.
- pregnant and lactating women due to the great need of the fetus and child for zinc.
- Alcoholics, as the use of products containing alcohol reduces the absorption of zinc in the intestines and increases the excretion of zinc in the urine.
Correcting a deficiency requires first identifying the cause of the deficiency and then increasing your zinc intake through diet or supplements as directed by your doctor.
Excess zinc in the body
Excess zinc is a disease associated with overdose or zinc poisoning. During the investigation, it was found that the first symptoms of poisoning occur when you take more than 100 mg of zinc per day. Excess zinc occurs in the vast majority of cases due to the intake of a large number of supplements and not foods high in this element.
Symptoms of excess zinc in the body:
- nausea, vomiting;
- poor appetite;
Once the causes and symptoms of poisoning have been identified, the patient is prescribed antiemetic and plenty of fluids, as well as special medications.
Zinc accumulates in the body
Taking zinc supplements regularly up to an acceptable upper level (which is mentioned in the supplement instructions) is generally considered safe. Overdosing on a complete diet can be especially dangerous for pregnant and breastfeeding women.
Long-term overdose of zinc supplements can suppress the immune system, lower “good” cholesterol (high-density lipoprotein, HDL), cause hypochromic anemia (low hemoglobin levels in the blood) and copper deficiency. Excessive zinc intake (over 100 mg per day) also increases the risk of prostate cancer.
Which foods contain zinc?
|Product||Content, mg per 100 g of product *|
|Cheddar or mozzarella cheese||3.2|
* According to the USDA
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