From 3 months before pregnancy to 3 months after pregnancy, one pill of 400 micrograms of folic acid a day is the common sense of every pregnant woman and mother-to-be.
Folic acid, or vitamin B9, is often called the "vitamin for pregnant women" and "the patron saint of the fetus" because it is closely related to the concept of life. Now, we all know that folic acid can effectively prevent fetal neural tube defects. Initially, when scientists studied the functions of folic acid on the human body, they did not understand its role in preventing fetal neural tube defects, but found that it can prevent a pernicious anemia that women are susceptible to during pregnancy. Since then, researchers have explored the medical and nutritional value of folic acid through scientific experiments and investigations, and the "18 martial arts" of this vitamin has gradually become known.
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Lack of folic acid can cause megaloblastic anemia
Folic acid plays an extremely important role in cell division and tissue growth. Therefore, when folic acid is deficient, it will first affect the tissues with faster cell proliferation.
Megaloblastic anemia refers to a type of anemia caused by DNA synthesis disorders, referred to as "megaloblastic anemia". This type of synthesis disorder is related to the lack of folic acid and vitamin B12.
Red blood cells are cells that renew quickly in the human body, with an average lifespan of 120 days. When folic acid is deficient, the proliferation of young red blood cells in the bone marrow slows down and stays at the megaloblast stage, maturation is blocked, the cell volume increases, and the chromatin in the nucleus becomes loose, resulting in an increase in the huge and immature red blood cells in the bone marrow. Folic acid deficiency can also cause a decrease in hemoglobin synthesis, which eventually leads to megaloblastic anemia.
The clinical manifestations of "megababy anemia" are firstly anemia, which usually manifests as moderate to severe anemia, with symptoms such as dizziness, fatigue, palpitations, and shortness of breath. Patients with severe symptoms may have mild jaundice, and may also be accompanied by white blood cell and thrombocytopenia ; Secondly, symptoms of the digestive tract, such as recurrent glossitis, loss of appetite, loss of taste, abdominal distension, diarrhea and so on.
In 1931, when British physiologist Lucy Wells was doing research in India, it was found that poor local women are prone to get a form of pernicious anemia when pregnant. There is a nutritional factor in yeast that can prevent and treat this disease. This factor was originally called the "Wells factor". Ten years later, scientists isolated this nutritional factor from spinach leaves and named it "folic acid."
In 1945, scientists discovered that this nutrient from spinach leaves is "Pteroyl Glutamate", which belongs to the B vitamins. In English literature and English popular science books, folic acid is called folate and folic acid respectively, and the Chinese translation is both "folate", but there are still differences between the two. Folate refers to folic acid found in natural foods, and folic acid refers to artificial chemically synthesized folic acid. Although the physiological functions of the two after entering the human body are exactly the same, their existence form and bioavailability are quite different. Folate needs a series of digestion and hydrolysis processes before it can be absorbed by the body, and the bioavailability is only 50%, while the bioavailability of folic acid is 100%. Therefore, pregnant women should take folic acid preparations instead of relying solely on natural foods to obtain this nutrient.
Supplementing folic acid can reduce the occurrence of neural tube defects
What really makes folic acid famous is a serious birth defect-neural tube deformity.
The neural tube is the central nervous system of the fetus. On the 15th to 17th days of embryonic development, the nervous system begins to develop. On the 22nd day of embryonic development, the two sides of the nerve folds begin to move closer to each other, and finally form a tube, namely the neural tube, the anterior hole of the neural tube and the tail end. The posterior foramen of the neural tube were closed one after another on the 24th to 26th day of embryonic development.
The neural tube is the part where the embryo develops into the brain, spinal cord, back of the head and spine. If the neural tube fails to develop normally, defects in the above-mentioned parts may appear when the baby is born, mainly manifested as spina bifida, anencephaly, encephalocele, and cerebrospinal meningocele. Spina bifida and brainless children are the most common. Spina bifida refers to the failure of the spine bones to develop well, which causes the spinal cord that should be protected by the spine bones to protrude or is exposed to the body surface. The baby will have symptoms such as paralysis, incontinence, and mental retardation. The head of a brainless child is not fully developed, and the skin, skull and even the brain are not fully developed. This kind of fetus is usually stillborn before birth, even if it is born, it will die within a short time.
my country used to be a country with a high incidence of neural tube defects. In May 1983, Professor Yan Renying, a well-known medical expert known as the "Mother of Perinatal Health Care in China," released a set of data at the "European China Perinatal Health Care Monitoring Seminar". A 3-year pilot study conducted in 7 villages in Shunyi, Beijing found that neural tube malformations accounted for the first cause of neonatal death; the death rate of neural tube malformations was about 7‰, much higher than the world average of 1‰ at that time .
From 1986 to 1987, the nationwide newborn birth defect monitoring data showed that, with the exception of Tibet, the total incidence of birth defects nationwide was 13.01‰, and the total incidence of neural tube defects was 2.74‰, ranking first among all birth defects. Based on this calculation, there are about 80,000 to 100,000 cases of neural tube defects born in my country every year, and 1 out of every 4 cases of neural tube defects born in the world is in China.
The cause of neural tube defects is the lack of folic acid in the mother. Since early pregnancy is a critical period for the differentiation of the fetal organ system and the formation of the placenta, the growth and reproduction of cells are very vigorous, leading to a substantial increase in the demand for folic acid by pregnant women, which is about 4 times that of ordinary people. The human body cannot synthesize folic acid and can only rely on external supplementation. The survey at the time showed that one in every three Chinese women of childbearing age lacked folic acid.
In 1988, the Ministry of Health of our country formally established a national birth defect monitoring network. In order to improve the high-detection symptoms of neural tube malformations in my country, Chinese medical experts have proposed international cooperation and scientific research. After several twists and turns and hard work, in September 1990, the "Sino-U.S. Research Cooperation Project on the Prevention of Neural Tube Malformations" was approved by the U.S. Congress. Research results confirmed for the first time that low-dose folic acid (now known as Silian folic acid tablets) can effectively prevent birth defects.
In 1993, the Ministry of Health of our country decided to conduct a promotion test among 16 million people in 30 counties and cities in Shanxi, Hebei, Jiangsu, and Zhejiang, and put a total of 17 million Silian folic acid tablets. After gaining experience, they will be promoted nationwide. After 3 years and nearly 250,000 cases of large-scale evidence-based medicine research, it is proved that folic acid supplementation can reduce 85% of neural tube defects in northern China. It is a simple and economical method suitable for my country and other developing countries to prevent neural tube defects. This research result has been published in "New England Journal of Medicine", "Chinese Medical Journal", "Lancet" and other professional medical journals, making my country the first country in the world to take measures to prevent neural tube defects nationwide. .
A small drop of folic acid made the neural tube deformity vacate the first place from the birth defect list in our country, and then dropped out of the top 5. By 2012, neural tube malformations had dropped to 9th place on the list.
More than 80 countries around the world have fortified folic acid
In fact, folic acid is widely present in various foods, especially dark green leafy vegetables, citrus, beans, and whole grains. But folic acid in food is very unstable, and folic acid is a water-soluble vitamin, it is easy to lose during cooking. As mentioned earlier, only 50% of natural folic acid can be absorbed by the body, so most people have difficulty getting enough folic acid from food. For example, the folic acid content in every 100 grams of leafy greens is as high as 160 micrograms, but due to the shortcomings of stability and absorbability, one kilogram of leafy greens must be eaten a day to meet the folic acid needs of pregnant women, which is almost impossible.
In order to prevent birth defects, the US Department of Health proposed in 1996 to supplement artificial folic acid in cereals. In 1998, this proposal became law, and the folic acid-fortified flour policy was enforced from January 1 of that year. Based on the estimated amount added, each American can supplement about 200 micrograms of folic acid every day. The effect of this measure is very obvious. One year later, the incidence of neural tube malformations in the United States has been reduced by 26%, while the overall level of plasma folic acid in the American population has generally increased, and the incidence of cardiovascular and cerebrovascular diseases has also decreased.
Canada also took the same measures in 1998, and the effect was equally obvious. The incidence of neural tube defects was reduced by 46%.
The United Kingdom has the highest incidence of neural tube defects in Europe, and the British public has been calling on the government to implement mandatory measures to increase folic acid intake. In 2018, thanks to the long-term efforts of doctors, scientists and infant health campaigners, the British government has approved the policy of "adding folic acid to flour".
According to the "2018 Global Nutrition Report", at least 86 countries around the world have implemented folic acid fortification policies.
Folic acid makes "tadpoles" more vigorous
Many men believe that preparing for pregnancy is mainly a matter for the wife, and what they have to do is to stay away from tobacco and alcohol and make their wives happy.
In fact, men also have to enter the role of "pregnant father" and adjust their bodies to the best condition through physical exercise and nutritional supplements. After all, gestating life is a matter for a couple.
Maybe the husband who loves his wife will pass a capsule of folic acid to her hand every night, but in fact this gentleman should also take one capsule. Yes, "pregnant dad" is also a group of people who need to supplement folic acid. Folic acid is an important substance to improve sperm quality. If the content of folic acid in the male body is low, then the quantity and mobility of sperm will be reduced, which reduces the chance of conception for women.
Studies have shown that the folic acid deficiency in the body can be effectively improved after taking folic acid daily for 4 weeks. The sperm formation cycle is as long as 3 months, so the pregnant dad should start taking folic acid at least 3 months in advance, and consume 400 micrograms a day, and stop using it after the wife is pregnant with the baby.
Folic acid can prevent stroke
In September 2020, my country's first "Chinese Multidisciplinary Expert Consensus on Clinically Reasonable Folic Acid Supplementation" was released. This consensus has gathered a large amount of evidence-based evidence at home and abroad, and has given precise and personalized guidance on the rational supplementation of folic acid from the perspectives of nutrition, pharmacy and multiple clinical disciplines.
Researchers have found that supplementing folic acid can prevent cardiovascular and cerebrovascular diseases and reduce the risk of stroke. At present, cardio-cerebrovascular diseases represented by myocardial infarction and stroke rank first among the death factors in our country, accounting for more than 40% of the total deaths, and the overall disease burden exceeds the sum of all types of cancer. In particular, stroke, commonly known as "stroke", has the characteristics of high morbidity, high mortality, and high disability. Compared with developed countries, the stroke mortality rate of Chinese residents is 3.5 times that of Japan and 5 times that of European and American countries.
After a large number of studies conducted by my country’s cardiovascular and cerebrovascular experts, it has been found that elevated blood homocysteine (HCY) is one of the chief culprits for the high incidence of strokes in Chinese residents, and is the biggest accomplice of strokes in patients with hypertension.
Homocysteine is an intermediate product in the metabolism of methionine, an essential amino acid for the human body. Factors such as nutritional intake, genetic factors, lifestyle habits, and drugs will all affect the level of homocysteine. Once the content of homocysteine in human blood exceeds a certain concentration, it will damage the endothelial cells of small blood vessels, aggravate the coagulation process, and cause atherosclerosis and thrombosis.
There are 300 million hypertensive patients in my country, of which 50% to 80% are "accompanied by elevated homocysteine levels." Experts named this type of hypertension "H-type hypertension". These patients have strokes. The risk is 10 to 28 times that of the normal population. "Folic acid supplementation can reduce homocysteine by more than 20%, thereby significantly reducing the risk of stroke by 25%." This scientific research result of Chinese experts has appeared in the famous medical journal "The Lancet".
In the human body, folic acid must be metabolized by the liver into active tetrahydrofolate to participate in various metabolic processes, and 5-methyltetrahydrofolate is the main form of its existence in plasma. This substance not only affects the metabolic process of DNA by participating in the synthesis of nucleic acid and protein, but also provides methyl groups for the methylation of homocysteine in the blood, thereby maintaining the normal level of homocysteine. When folic acid is lacking, it will cause homocysteine metabolism disorder, leading to increased plasma homocysteine levels. Chinese scientists have carried out the "Chinese Stroke Primary Prevention Study" to verify the adverse event chain of "low folate-high homocysteine-high stroke incidence" in hypertensive patients in my country.
Folic acid improves cognitive function
Studies have found that folic acid supplementation can help improve cognitive function and reduce the risk of Alzheimer's disease.
Cognitive function refers to the various conscious mental activities that human beings always exist in the state of awakening. Cognitive dysfunction, ranging from mild cognitive impairment to severe dementia. In addition to the natural aging of the human body, there are many factors that cause cognitive dysfunction. In the middle of the 20th century, British scientists discovered that pernicious anemia is often accompanied by neuropsychiatric symptoms, which can be reversed after taking folic acid and vitamin B12. From this, people have gradually realized the relationship between folic acid deficiency and cognitive dysfunction.
Current research has found that folic acid deficiency is related to many diseases such as dementia, depression, and Alzheimer's disease. In a study conducted on elderly people aged 60 to 90, it was found that increasing plasma folic acid can significantly improve the overall cognitive ability and mentality of the elderly; a folic acid intervention study conducted in people over 50 years old showed that taking 800 per day People with micrograms of folic acid had significantly better short-term memory, mental agility, and language fluency than the control group who took placebo daily. At the same time, folic acid deficiency can lead to increased homocysteine levels, which can also damage the normal brain function.
In addition, folic acid supplementation can also increase the body's insulin sensitivity and reduce the risk of diabetes. Folic acid supplementation can also significantly delay the development of kidney disease in patients with hypertension and reduce the risk of chronic kidney disease developing into uremia.
