Zinc deficiency disease
Introduction
Introduction to zinc deficiency Zinc is one of the essential trace elements in the human body and is widely involved in various metabolic activities as a component of various enzymes. Zinc deficiency can cause anorexia, short stature, sexual maturity disorders, low immune function, rash and hair loss. Human colostrum has a high zinc content, and zinc absorption and utilization rate in human milk is also high, so breastfeeding of infants is beneficial for preventing zinc deficiency. However, with the increase of age, it is necessary to add food supplements on time, such as egg yolk, lean meat, fish, animal offal, beans and nuts, which are rich in zinc, and should be properly arranged daily. Artificial breastfeeding without breastmilk is best done with infant formula or milk powder that is fortified with moderate amounts of zinc. Pay attention to its zinc content, long-term consumption of a variety of foods that strengthen zinc, too much zinc can cause poisoning. If excessive intake of zinc can cause acute zinc poisoning, such as vomiting, diarrhea and other gastrointestinal symptoms, zinc-deficient people must choose to take zinc supplements. basic knowledge The proportion of illness: 0.0006% Susceptible people: children Mode of infection: non-infectious Complications: Pediatric enteric acral dermatitis Pediatric malnutrition
Cause
Cause of zinc deficiency
Insufficient intake (25%):
Plant-based foods such as cereals contain less zinc than meat, and egg-milk and other animal foods. Therefore, vegetarians are prone to zinc deficiency. The growth period and malnutrition recovery period are more than zinc requirements. Pregnant women and lactating mothers need more zinc. Insufficient intake can cause mother and fetus, zinc deficiency in children, and total parenteral nutrition such as lack of zinc or zinc can cause severe zinc deficiency, infection, zinc demand increases when fever, while appetite decreases, intake decreases, Easy to cause zinc deficiency.
Malabsorption (20%):
Diarrhea caused by various reasons can reduce the absorption of zinc, especially chronic diarrhea such as malabsorption syndrome, steatorrhea, cystic fibrosis of the parotid gland, cereals containing more phytate and crude fiber, hindering zinc Absorption, the amount of zinc in milk is similar to that of breast milk, about 45.9 ~ 53.6mol / L (300 ~ 350g / dl), but the absorption of zinc in milk is not as good as zinc in breast milk.
Too much loss (15%):
Such as repeated blood loss, hemolysis, trauma, burns can cause a large amount of zinc to lose with body fluids; cirrhosis, chronic uremia and other high zincuria caused by hypoalbuminemia, some drugs such as long-term application of metal chelators (such as green Moldy amine, etc.) and repeated intravenous infusion of the near acid salt, combined with zinc excreted from the urine, can cause zinc deficiency.
Genetic defects (15%):
For example, acrodermaitis enteropathica (AE) is a rare autosomal recessive disorder. Due to the functional defects of zinc absorption in the small intestine, the zinc content in the body is reduced, plasma (clear) zinc, red blood cell zinc, muscle zinc. Zinc and urinary zinc are reduced, and there are acral skin lesions, intractable diarrhea, alopecia and growth and development disorders, and immunity is reduced and susceptible to infection.
Prevention
Zinc deficiency prevention
First, preventive health care:
1. Breastfeeding the baby.
2. Add food supplements on time.
For infants who are not breastfed, it is best to take infant formula or milk powder with an adequate amount of zinc.
Eat foods rich in zinc daily, such as lean meat, fish, egg yolk, animal offal, beans and nuts.
3. When children have fever and diarrhea for a long time, they should pay more attention to supplement zinc-containing foods.
Second, the daily zinc (element) supply recommended by the Chinese Nutrition Society in 1988 is:
From birth to 6 months: 3mg.
6 months or more to 1 year old: 5mg.
1 year old to 10 years old: 10mg.
10 years old or older: 15mg.
Pregnant women and lactating mothers: 20mg.
Third, note:
Long-term consumption of a variety of foods that strengthen zinc, but do not pay attention to the intake of zinc, can cause poisoning due to excessive zinc intake.
Excessive intake of zinc can cause acute zinc poisoning, and gastrointestinal symptoms such as vomiting and diarrhea.
Chronic zinc poisoning can have anemia and iron deficiency, and animal experiments can cause liver and kidney function and immune damage.
Zinc mist inhalation can have low fever and cold-like symptoms.
Complication
Zinc deficiency complications Complications Pediatric enteric dermatitis pediatric malnutrition
Complications: serum vitamin A can be reduced due to vitamin A metabolic disorders, resulting in night blindness caused by dark adaptation time, but also ecstasy, dwarfism, decreased immunity, sleepiness, mental disorders, mental retardation and so on.
Symptom
Symptoms of zinc deficiency disease Common symptoms Anorexia, loss of appetite, fatigue, diarrhea, immunity, decreased oral ulcer, hair loss, mental disorder
1, anorexia
In the absence of zinc, the taste buds are reduced, the taste acuity is reduced, the appetite is weak, and the food intake is reduced. The activity of the digestive enzymes such as carboxypeptidase A is reduced, and the digestibility is also weakened.
2, growth and development backward
Zinc deficiency hinders the synthesis of nucleic acids and proteins and reduces the consumption of food, affecting the growth and development of children. Children with zinc deficiency often have lower body weight than normal children of the same age, and severe cases have dwarfism. Domestic and foreign reports of zinc deficiency in children after zinc supplementation, body weight recovery is faster, zinc deficiency can affect children's intelligent development, severe mental disorders, zinc supplementation are effective.
3, adolescent sexual developmental delay
For example, male genital testicles and penis are too small, testosterone content is low, sexual function is low; female breast development and menstrual cramps are late; male and female pubic hair are late. The second sexual characteristics appear several weeks to several months after zinc supplementation, and the above symptoms are alleviated or disappeared.
4, pica
Zinc-deficient children may have the phenomenon of eating mud, wall skin, paper, cinder or other foreign matter, and the zinc supplementation effect is good.
5, susceptible to infection
Cellular immunity and humoral immunity of zinc-deficient children may be reduced, and are susceptible to various infections, including diarrhea.
6, skin mucosa performance
When zinc deficiency is severe, there may be various rashes, bullous dermatitis, recurrent oral ulcers, long-term unhealed lower extremity ulcers, and alopecia of varying degrees.
7, fetal growth and development, multiple deformities
Severe zinc deficiency pregnant women and pregnant animals can cause fetal growth and development and various deformities, including neural tube defects. Maternal factors are weak in contraction and prolonged labor and excessive bleeding.
8, other
Such as mental disorders or sleepiness, and due to vitamin A metabolic disorders, serum vitamin A decreased, dark adaptation time, night blindness.
Examine
Zinc deficiency check
1, medical history and physical examination
Understand feeding history such as low zinc content in the diet, or long-term malabsorption such as chronic diarrhea. These other symptoms and signs of taste sensitivity and loss of appetite, growth and development, and project unequal.
2, laboratory diagnosis of blood
Blood biochemical examination: plasma (or serum) zinc is lower than normal, below the normal low limit of 10.0 to 10.7 mol / L (65 ~ 70 g / dl). Generally, serum zinc is slightly higher than plasma zinc. Because some zinc is released from red blood cells and platelets, the longer the blood is taken, the higher the zinc determination value. Plasma should be separated and measured immediately after blood collection. Note that blood should be taken to avoid hemolysis, because red blood cell zinc is more than 10 times higher than plasma zinc. Specimens should not be contaminated, rubber stoppers and plasters should contain zinc and should be avoided. Plasma (clear) zinc is affected by the zinc content of the recent diet. Liver and kidney diseases, as well as acute and chronic infections and stress states, can reduce plasma (clear) zinc.
Diagnosis
Diagnosis and identification of zinc deficiency
1, laboratory diagnosis
Plasma (or serum) zinc is lower than normal, below the normal low limit of 10.0 ~ 10.7mol / L (65 ~ 70g / dl), generally serum zinc is slightly higher than plasma zinc, due to part of zinc released from red blood cells and platelets, take The longer the blood distance measurement is, the higher the zinc determination value is. The blood should be separated and measured immediately after taking blood. It is necessary to avoid hemolysis when taking blood, because the red blood cell zinc is more than 10 times higher than the plasma zinc; the specimen is not contaminated, the rubber stopper and the rubber stopper The adhesive plaster contains zinc and should be avoided. Plasma (clear) zinc is affected by the zinc content of the recent diet. Liver, kidney disease and acute, chronic infection and stress can all decrease plasma (clear) zinc.
Zinc may be a reference indicator for chronic zinc deficiency. Zinc is affected by various conditions such as hair growth rate, environmental pollution, washing method and collection site, and is not closely related to plasma zinc. It is not a reliable indicator for diagnosing zinc deficiency.
Zinc is involved in the formation of the active phosphatase activity center, so serum phosphatase activity can help to reflect the zinc nutrition status of infants and young children, which decreases when zinc deficiency occurs, and then increases after zinc supplementation.
White blood cell zinc is an indicator that reflects the zinc nutrition level of the human body. However, it requires more blood during the measurement (currently at least 5 ml of blood is needed in China), and the operation is complicated, and it is difficult to promote clinically.
In recent years, it has been studied at home and abroad to determine the concentration of metallothionein by measuring the concentration of metallothionein by the stable isotope method to understand the nutritional status of zinc.
2, experimental treatment
When suspected of zinc deficiency, it can be treated with a single zinc agent. If the effect is obtained quickly, it will help to confirm the diagnosis.
3, differential diagnosis
The diseases that need to be diagnosed clinically with this disease are: porphyria, phenothiazine poisoning, liver disease, etc.
