Vitamin B1 deficiency in children

Brief introduction of vitamin B1 deficiency in children Vitamin B1 deficiency (vitamin B1 deficiency), also known as beriberi (beriberi), is due to the lack of vitamin B1 (also known as thiamine) in the body. It is mainly caused by the symptoms of the digestive system, nervous system and cardiovascular system. A region where white rice is the staple food. The amount of vitamin B1 in the adult body is 30 mg, which is converted to 1 mg per day. Normal people do not have symptoms when vitamin B1 is deficient for 2 to 3 weeks. basic knowledge The proportion of sickness: 0.01% Susceptible people: children Mode of infection: non-infectious Complications: polyneuritis, heart failure

The cause of vitamin B1 deficiency in children

Insufficient intake (30%):

The content of vitamin B1 in breast milk is lower than that of milk, the content in breast milk is 16 g/ml, and the content in milk is 42 g/ml, but the vitamin B1 content in breast milk is sufficient for the growth of infants. If the intake of vitamin B1 in the diet of the mother is lacking, it will cause the deficiency of vitamin B1 in the breast milk. If not added in time, the breast-fed infant will also cause vitamin B1 deficiency.

Absorption barrier (25%):

If you have digestive diseases, such as chronic diarrhea, chronic diarrhea, gallbladder fibrosis, intestinal infections, etc., can reduce the absorption of vitamin B1. Liver and kidney diseases will affect the synthesis of TPP, resulting in vitamin B1 deficiency. Vitamin B1 deficiency reduces the acidity in the gastric juice, thereby reducing the release of vitamin B1 in the vitamin B1 complex in the gastrointestinal tract, affecting the absorption of vitamin B1.

The need for vitamin B1 is increased (25%):

Children grow faster and need more. If children suffer from tuberculosis, measles, chickenpox, pneumonia and high fever, or have diseases with increased metabolic rate such as hyperthyroidism, the consumption of vitamin B1 increases. Failure to replenish in time will result in a deficiency of vitamin B1.

Genetic metabolic disorders (20%):

Hereditary vitamin B1 metabolism and dysfunction, caused by vitamin B1 deficiency, generally have a high history of familial hereditary disease, or a history of marriage of parents and close relatives.

(two) pathogenesis

Vitamin B1, also known as anti-berexia factor or anti-neuritis factor, is one of the first vitamins found. Vitamin B1 is easily destroyed in high temperature, especially high temperature alkaline solution, and has good stability in acidic solution. In vivo, 80% of thiamine is in the form of thiamine pyrophosphate (TPP), 10% is in the form of thiamine triphosphate, and the rest is thiamine monophosphate or free thiamine. Prime. In the body, 80% of thiamine is in the form of TPP, which is a cofactor for the pyruvate oxidative decarboxylase system and a coenzyme for the conversion of carboxyacetaldehyde in the hexose phosphate oxidation branch. Therefore, vitamin B1 is closely related to glucose metabolism, and its lack of sugar metabolism is blocked, energy production is reduced, and a series of pathological changes are produced.

1. The nervous system, especially the peripheral nerve, is severely damaged, myelin degeneration and pigmentation. The myelin of the central nervous system and the peripheral nervous system is poorly developed, and thus manifests as irritability. The severed nerve axis is destroyed, and the involvement of the sciatic nerve and its branches is more common and occurs earlier. Others such as the forearm nerves can also be involved.

2. Cardiovascular system due to lack of energy, myocardial weakness, peripheral vascular smooth muscle tension decreased, small blood vessels dilated. The heart is enlarged and thick, especially in the right heart. Myocardial edema, its myocardial fibers are coarse and hard. The blood vessels are congested, but the tissue structure is normal.

3. Tissue edema and serous effusion tissue edema is more common in the lower limbs, and the body cavity slurry can also ooze out.

4. Muscle atrophy occurs in the muscles innervated by the affected nerves. Microscopically, muscle fiber transverse stripes disappeared, turbid swelling and fatty degeneration.

5. Digestive system The smooth muscle tension of the digestive tract is reduced, affecting gastrointestinal motility, and digestive function is weakened.

Prevention of vitamin B1 deficiency in children

1, to keep the feet clean and dry, sweat feet to be treated. Change shoes and socks, people with tight toe seams can be sandwiched in the middle of the paper, to absorb water and ventilation. Shoes should be well ventilated.

2, do not use other people's slippers, bath towels, wipes, etc., do not walk in the bathhouse, sewage next to the pool.

3, public baths, swimming pools to do sewage treatment, disinfection with bleach or chloramine, to form a system to prevent mutual infection of athlete's foot.

4, anti-shoe cabinet infection athlete's foot.

Pediatric vitamin B1 deficiency complications Complications, polyneuritis, heart failure

1. Nervous system polyneuritis, severe cases can occur intracranial hypertension.

2. Acute heart failure occurs when heart failure is severe.

3. Organ venous congestion, pulmonary congestion and hepatic congestion; pericardial cavity, thoracic cavity and peritoneal effusion.

4. The body has a skin sputum infection in the rest of the body. Due to long-term suffering from ankle or autologous inoculation after hand rubbing, athletes with ankle can be combined with hyperthyroidism, handcuffs, and body lice. When combined with hyperthyroidism, the deck is turbid, opaque, cloud-like, stain-like, and the surface is tarnished.

Pediatric vitamin B1 deficiency symptoms common symptoms anorexia irritability, abdominal distension, diarrhea, abdominal pain, nausea, constipation, loss of appetite, difficulty in swallowing

Deficiency of thiamine will cause beriberi, which is the end result of insufficient thiamine intake, mainly affecting the cardiovascular and nervous systems. Mainly manifested as polyneuritis, muscle atrophy, tissue edema, heart enlargement, circulatory disorders and gastrointestinal symptoms. The incidence of infants is often caused by insufficient vitamin B1 in the lactating mothers. Vitamin B1 deficiency often has a lack of niacin.

Infant beriberi

Infants, which occur more than a few months, are acute and sudden, more elusive than adults, and can present a variety of clinical manifestations, but with cardiovascular symptoms predominating.

(1) Digestive system symptoms: The initial manifestations are mainly digestive symptoms such as loss of appetite, anorexia, nausea, vomiting, inability to digest stools, sometimes bloating, constipation, abdominal pain or diarrhea.

(2) Neurological symptoms: Neurological symptoms appear shortly after the appearance of symptoms of the digestive system, and those with prominent neurological symptoms can be classified into brain type or neuritis type. In the early days, there was irritability, crying, and nighting. The brain type is mainly characterized by episodes of crying like abdominal pain, irritability, fullness of the front and back. In severe cases, cerebral congestion, intracranial hypertension, coma and death may occur. Peripheral neuritis mainly manifests as limb sensory disturbance, peripheral paralysis, early manifestations of limb weakness, followed by increased symptoms and limited dorsiflexion of the toes. The Achilles tendon reflex and knee reflexes are initially enhanced, then weakened and eventually disappear. Soft palate reflex barrier, coughing and difficulty in swallowing. If there is neuritis, there is weak muscle strength, reduced tendon reflexes, and even muscle atrophy. If the brain is involved, there may be drooping eyelids, optic atrophy, and difficulty swallowing. It is hoarse when it involves the recurrent laryngeal nerve. Later, there is an increase in intracranial pressure or fullness of the front, and unconsciousness.

(3) Cardiovascular symptoms appear palpitations, tachycardia, infants can appear galloping, difficulty breathing, late cyanosis, heart enlargement, heart failure. Pulmonary congestion and liver congestion. If not treated in time, he will die soon.

2. Edema and serous effusion

Edema can spread throughout the body, mostly in the lower limbs, serous effusion, can occur in the pericardial cavity, chest and abdominal cavity. Loss of sound due to edema of the throat, or a special throat (sickness of beriberi).

Pediatric vitamin B1 deficiency check

To evaluate the nutritional status of thiamine by measuring urinary thiamine excretion before and after thiamine loading, serum thiamine level, erythrocyte transketolase (ETK) activity, and fasting determination of thiamine/creatinine in urine Laboratory tests such as ratios are evaluated.

1. Thiamine loading test Excessive intake of vitamin B1 will be excreted from the urine, so the vitamin B1 in urine can be used to estimate the state of vitamin B1 in the body, because the amount of thiamine required and its urinary excretion Has a certain relationship, so the thiamine load test can determine the nutritional status of thiamine. The thiamine is usually measured by fluorescence or microbiological method. The testee fasts after urinating in the morning, and gives vitamin B1 (oral 5mg or intramuscular injection 1mg), then drinks 200ml, collects 4h urine, and measures the amount of vitamin B1 in urine. If it is normal at 100 g or more, the athlete's foot is often less than 50 g.

2. Serum thiamine levels Because the content of free thiamine and its phosphate in the blood is very low, the measurement of thiamine levels in blood as an indicator of thiamine nutritional status has not been widely adopted, but recently Using sensitive high-performance liquid chromatography, this method is simple and reliable, and easy to standardize. However, due to its wide range of reference values and unstable blood content, it can not reflect the early lack of conditions in time, so it is rarely used in clinical practice. The normal reference value is 103-306 nmol/L (3.1-9.2 g/dl). If the serum thiamine level is <100 nmol/L (3 g/dl), it indicates vitamin B1 deficiency.

3. Erythrocyte transketolase (ETK) activity This is a specific indicator for determining the nutritional status of vitamin B1, and is the most effective indicator for evaluating the nutritional status of vitamin B1. ETK has changed before the onset of clinical vitamin B1 deficiency, so it is called subclinical diagnosis or edge state examination. The ETK activity was measured by measuring the pentose disappearance rate or the hexose occurrence rate in the dissolved red blood cells. Determination of the activity of ETK after in vitro (basic) or addition of TPP (stimulation), usually based on basal activity (ETKA) or the difference between post-stimulation activity and basal activity as a percentage of basal activity (ETK-AC activity coefficient or TPP effect) )To represent. Thiamine deficiency and ETKA reduction are associated with an increase in ETK-AC; the higher the ETK-AC value, the more severe the thiamine deficiency. The normal reference value of the TPP effect is 0 to 15%, the vitamin B1 is 16% to 20% at low levels, and >20% in the absence.

4. Determination of thiamine/creatinine ratio in urine. Determination of thiamine/creatinine ratio in urine by a fasting test. The normal value is 176 g/g creatinine, if the infant is less than 120 g/g creatinine, the child aged 4-12 years is less than 60 g. /g creatinine, which is vitamin B1 deficiency.

Should be chest X-ray, ECG and B-ultrasound, if necessary, do brain CT to help diagnose and differential diagnosis. Electrocardiogram examination has tachycardia, low voltage, T wave low or inversion, QT interval extension and so on.

Diagnosis and identification of vitamin B1 deficiency in children

diagnosis

Reliable diagnosis can be made by relying on medical history, clinical signs and symptoms, laboratory tests and experimental thiamine treatment.

History

Whether the child has insufficient intake of vitamin B1, and whether there is long-term consumption of white rice, noodles, and partial eclipse for children who have added complementary food. Whether there are diseases that impede the absorption and utilization of vitamin B1, such as chronic depletion diseases, gastrointestinal diseases, hepatobiliary diseases, and the like. Whether the patient has increased factors for the increase in thiamine requirements, such as growth and development, fever and hyperthyroidism.

2. Clinical features

The presence or absence of peripheral neuritis manifests as muscle atrophy, paresthesia, abnormalities in the Achilles tendon and knee reflex. Whether there is progressive edema. The heart expands hypertrophy, heart rate increases, and pulse pressure increases. It can exclude heart failure from other heart diseases. There are no signs of other nutritional deficiencies.

3. Laboratory inspection

It can be diagnosed by measuring the urinary thiamine excretion before and after thiamine loading, serum thiamine levels, erythrocyte transketolase (ETK) activity, and laboratory tests such as thiamine/creatinine ratio in urine. .

Differential diagnosis

1. Acute pharyngitis is mainly caused by upper respiratory symptoms such as hoarseness, cough, and aphasia, and is easily misdiagnosed as acute pharyngitis.

2. Digestive dysfunction is mainly caused by loss of appetite, abdominal distension, diarrhea, constipation, liver enlargement and other gastrointestinal symptoms, and is easily misdiagnosed as enteritis or indigestion and digestive disorders.

3. Viral encephalitis is characterized by sluggish eyes, ambiguity, unresponsiveness, lethargy, coma, convulsions and other neurological symptoms, and is easily misdiagnosed as viral encephalitis.

4. When kidney disease has different degrees of edema, it is differentiated from etiology such as kidney disease and decreased plasma protein.

5. Myocardial damage is differentiated from myocardial damaging diseases when there are circulatory symptoms.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.