Many pregnant mothers are very familiar with folic acid and have been taking it since pregnancy. However, few people may know about the origin of folic acid, so I will bring it to you today.folic acid"The story.
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Discovery and application of folic acid
The function of folic acid was first determined by an English doctor named Lucy Wells. In the 1930s, she went to Mumbai, India to practice medicine, and found that there were many pregnant women suffering from pernicious anemia (medically called megaloblastic anemia). The volume of red blood cells in patients’ blood was increasing, but the red blood cell count was decreasing.
There is a folk prescription that can treat this anemia, and its main component is a fermented liver product. Lucy Wells separated various components from this fermented extract, and tried one by one, and finally proved that it was rich in vitamin B folic acid.
In 1941, an American scientist Michelle purified folic acid from spinach leaves and found out its structure and molecular formula. In 1946, scientists successfully synthesized folic acid and began to study its mechanism of action.
The research results surprised scientists. It turns out that this humble small molecule compound is actually a coenzyme necessary for DNA replication in human body. Without it, DNA replication cannot be carried out and cells cannot divide. However, the synthesis of protein in cells is not affected, so the protein in red blood cells will accumulate more and more, and the volume will naturally increase, but the number will not increase, which is the cause of anemia.
The developing fetus undergoes a lot of cell division every day, which requires a lot of folic acid. The folic acid in pregnant women is requisitioned in large quantities, resulting in its own anemia (pernicious anemia).
Based on historical reasons, China is one of the countries with high incidence of birth defects (including anencephaly, spina bifida, cleft palate and neural tube malformation).
In the early 1980s, Professor Yan Renying of Peking Union Medical College Hospital, the mother of perinatal health care in China, accidentally found that the incidence of neural tube malformation was as high as 0.7% in rural areas of Shunyi County, Beijing, which was the first cause of perinatal death. Professor Yan Renying realized the seriousness of the situation and was very anxious, and immediately reported it to the State Council.
From 1993 to 1996, Chinese and American scientists and tens of thousands of grassroots health workers monitored the birth outcomes of nearly 250,000 cases in 30 cities and counties in four provinces in China, and confirmed that 0.4 mg folic acid daily supplement before and after pregnancy could effectively reduce the incidence of neural tube malformation by 85%. Expectant mothers should take folic acid supplementation in the first 10 weeks of pregnancy until the tenth week of pregnancy (at this time, the neural tube has been fully developed).
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Widespread application of folic acid
Folic acid has many uses, including intervention in hyperhomocysteinemia, H hypertension, birth defects, anemia, depression, Alzheimer’s disease, cognitive impairment, stroke, folic acid deficiency and so on.
Hyperhomocysteinemia
Homocysteine has two metabolic pathways in the body: a. methyl is converted into methionine through 5- methyltetrahydrofolate; B, entering a thio-transferring pathway to form cysteine and ketobutyric acid. Folic acid can promote the metabolism and excretion of homocysteine and reduce the level of homocysteine by inhibiting 5- methyltetrahydrofolate.
The best daily dose for treatment is 0.8 mg/day; For severe cases and patients with high homocysteine level, 2 mg/day can be taken for 3 years or until the homocysteine blood index is normal. Combined application with vitamins B6 and B12 may increase the efficiency by 7%, but taking vitamins B6 and B12 alone has no effect.
Infant birth defects and pernicious anemia
Folic acid is also called the patron saint of fetus, and small folic acid has great effect. In order to prevent birth defects (cleft palate, neural tube malformation), expectant mothers should start taking folic acid before pregnancy (10 weeks before pregnancy) until the 10 th week of pregnancy or the birth of the baby.
Malnutrition and pernicious anemia during pregnancy can be treated with folic acid until the blood picture is normal, supplemented by intramuscular injection of vitamin B12; Or oral cobalamin adenosine (coenzyme vitamin B12).
Prevention of stroke, dementia and depression
Studies have shown that taking 0.8 mg folic acid daily on the basis of taking the antihypertensive drug enalapril can reduce the incidence of stroke in hypertensive patients from 3.4% to 2.7%, and reduce the relative risk by 21%.
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Precautions for taking folic acid
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Step supplement vitamin B12
Folic acid can quickly correct the abnormal phenomenon of megaloblastic anemia and improve anemia, but it can’t prevent nerve damage caused by vitamin B12 deficiency, such as spinal cord degeneration. And if folic acid is still taken in large doses, vitamin B12 will be consumed due to vigorous hematopoiesis, which can further reduce the content of vitamin B12 in serum and make nerve damage develop.
Therefore, vitamin B12 should be taken together to improve neurological symptoms.
2. Visible allergic reaction
Occasionally, taking folic acid in large quantities for a long time may cause anorexia, nausea, abdominal distension and other symptoms. When taking a large amount of folic acid, yellow urine can appear.
3. Pay attention to supplementing potassium salt
After taking folic acid and vitamin B12 to treat megaloblastic anemia, especially in severe cases, serum potassium may decrease or suddenly decrease when hemoglobin returns to normal, so attention should be paid to supplementing potassium salt during this period.
folic acidIt is abundant in fruits and vegetables with green leaves, such as spinach, cabbage, tomato, cauliflower, carrot, onion, beans, asparagus, asparagus, Chinese cabbage, lentils, grapes, oranges, bananas, pears, cherries and pomegranates, or in liver and kidney of cattle and sheep, chicken, eggs, yeast, soybeans, walnuts, cashews and bread, but in white rice and cakes.
Natural folic acid is extremely unstable, easily oxidized by sunlight and heating, and can be destroyed by long-term cooking, so it is not suitable for green vegetables to be overcooked.
Part of the map source comes from the network.
Author/Peking University Fourth Clinical Medical College, Zhang Shige, beijing jishuitan hospital.
Editor/Government Affairs Service Center of Guangdong Food and Drug Administration (PAN)
Review/Zou Yuhua
Reporting/feedback