vitamin A toxicity
Introduction
Introduction to vitamin A poisoning Excessive intake of vitamin A in the human body can cause poisoning syndrome, called Vitamin Atoxicity. The earliest reported in the 1960s, the Arctic explorers suffered from headache, vomiting, and lethargy several hours after eating the polar bear liver. Because human and animal vitamin A 90-95% was stored in the liver, in recent years, due to the abuse of vitamin A in China. Concentrates, the number of people with symptoms of poisoning is increasing, mainly because parents lack the knowledge of rational application of vitamin A. It is believed that the more the dosage, the better, and the medical staff are also lack of vigilance, which deserves attention. According to the study, infants and young children take vitamin A, such as a dose of more than 300,000 international units (per gram of common cod liver oil containing vitamin A850 international units; per gram of concentrated cod liver oil containing vitamin A 5-65,000 international units), can cause acute poisoning, such as daily Taking 50,000-100,000 international units for 6 months or so can cause chronic poisoning. In addition, children may have greater individual differences in sensitivity and tolerance to vitamin A. Some children do not exceed cod liver oil. Mild symptoms of poisoning may also occur in the above range. basic knowledge Sickness ratio: 0.00045% Susceptible people: children Mode of infection: non-infectious Complications: headache, edema, disturbance of consciousness, narcolepsy, cerebral palsy, respiratory failure
Cause
Causes of vitamin A poisoning
Currently prepared cod liver oil preparations, there are two types of concentrated cod liver oil drops and pills, the ingredients of which are vitamin D and vitamin A. These two vitamins are very important for children in the growth stage, and vitamin D is mainly used. Prevention and treatment of rickets, and vitamin A plays an important role in ensuring the development and function of children's eyes, skin and other organs, but there is a problem that is often overlooked, that is, in these cod liver oil preparations, the content of vitamin A is higher than that of vitamin D. The content is much higher. If the preparation is used for children for a long time, or if the rickets are treated with a larger dose, it is easy to cause a large amount of vitamin A to accumulate in the body and cause toxicity. According to the study, infants and young children take vitamin A, such as When a dose exceeds 300,000 international units (per gram of common cod liver oil contains vitamin A850 international units.
Each gram of concentrated cod liver oil contains vitamin A 5-65,000 international units), which can cause acute poisoning. For example, taking 50,000-100,000 international units every day for 6 months or so can cause chronic poisoning. In addition, children have vitamin A There may be large individual differences in sensitivity and tolerance. Some children may also experience mild symptoms of poisoning when taking cod liver oil beyond the above range.
Prevention
Vitamin A poisoning prevention
Beijing applied vitamin AD to strengthen milk to feed infants, effectively preventing vitamin A deficiency, and no symptoms of excessive vitamin A.
Proper use of cod liver oil for children is the only measure to prevent poisoning, including:
1. Strictly follow the doctor's advice to take the cod liver oil preparation for the child. It should not be abused. It should not be used. Generally, infants under 1 year old can give 3-4 drops of concentrated cod liver oil per day, which should not exceed 6 drops.
2, prevention and treatment of infantile rickets, try to give children a pure vitamin mouth preparation without vitamin A.
3. If it is necessary to supplement the child with a large dose of vitamin A due to special circumstances, the doctor should strictly limit the time of administration.
4. When the child takes cod liver oil, once it is found to have suspicious symptoms of vitamin A poisoning, stop taking it immediately and take the child to the hospital for treatment.
Complication
Vitamin A poisoning complications Complications headache edema consciousness disorder narcolepsy cerebral palsy respiratory failure
More serious complications include sudden increase in intracranial pressure, sequelae left by first aid, and three main symptoms of intracranial pressure: headache, vomiting, optic nerve head edema, and changes in consciousness and vital signs: lethargy, brain Hey, go to the brain to be strong, breathing irregularly and even respiratory failure and die.
Symptom
Vitamin A Poison Symptoms Common Symptoms Abdominal Pain Skin Itching Hepatosplenomegaly Bone Softening Hair Loss Bone Pain Eyeball Tremor Muscle Pain Before Sputum Full Lip Cleft Palate
Vitamin A poisoning can be divided into the following two types:
1, acute type
Because the children have different individual sensitivity to vitamin A, and the amount of vitamin A stored in the liver is different, the poisoning dose can be quite different. Generally, vitamin A is injected 300,000 IU, which can cause symptoms of poisoning within a few days, which is characterized by loss of appetite. , irritability or lethargy, vomiting, anterior iliac bulging, enlarged head circumference, cranial rupture, papilledema, etc. Increased intracranial pressure is common in acute type, which may be caused by increased cerebrospinal fluid volume or malabsorption. Nervous system infection signs, sudden symptoms of increased intracranial pressure, combined with a large intake of vitamin A history, the symptoms disappeared quickly after the withdrawal of vitamin A, the diagnosis can be established.
2, chronic type
The dosage of vitamin A reaches tens of thousands of units per day. For example, infants and young children consume 1500 IU of vitamin A per kilogram per day. Symptoms of poisoning can occur in a few days. Early irritability, loss of appetite, low fever, excessive sweating, hair loss, and typical after Symptoms of bone pain, metastatic pain, may be accompanied by soft tissue swelling, tenderness and no redness, heat signs, long bones and limbs more common, due to long bones involved in osteophyte embedding, can lead to short stature, some cases have ankle , the posterior occipital swelling and pain, can be misdiagnosed as skull softening, symptoms of increased intracranial pressure such as headache, vomiting, anterior iliac crest and bulge, cranial suture separation, ocular strabismus, nystagmus, diplopia, etc. Characteristics, but less common than acute type, in addition, there are skin itching, scaling, rash, chapped lips, dry hair, hepatosplenomegaly, abdominal pain, myalgia, hemorrhage, kidney disease, and regenerative anemia with leukopenia, etc. Blood alkaline phosphatase has increased, and it has been reported in foreign countries that long-term liver and spleen can cause cirrhosis, increased portal pressure, and even death.
Examine
Vitamin A poisoning check
1. X-ray examination has special value for the diagnosis of this disease. It is characterized by abnormal shape of tubular bone, bone absorption, fracture; change of tarsal plate and soft tissue swelling; formation of new bone under the periosteum in the backbone; widening of cranial suture, full expansion of anterior .
2, cerebrospinal fluid pressure increased, up to 2.55kPa (260mmH2O), cells and sugar in the normal range, it was found that protein decreased or normal low value.
3, check serum vitamin A, often up to 1,000 ~ 6000g / L or more.
Diagnosis
Diagnosis and identification of vitamin A poisoning
The plasma vitamin A concentration ranged from 20 to 80 g/dl (0.7 to 2.8 mol/L) during normal fasting. When the vitamin A was poisoned, the fasting plasma concentration could exceed 100 g/dl (3.49 mol/L) and up to 2000 g/ In patients with dl (69.8 mol/L), differential diagnosis may be difficult because the symptoms are eccentric and bizarre, but usually include headaches and rashes.
