Vitamin B9 (commonly called folic acid, also known as folate, pteroylglutamic acid, folacin) is one of the essential nutrients that we can find in nature in the form of folates. The name comes from the Latin word folium, which means a leaf. Vitamin B9 was discovered in the 1930s. In 1941, it was isolated from spinach leaves, and in 1946 was synthesized by American chemists.
The biologically active form of vitamin B9 is levomefolic acid, or 5-methyltetrahydrofolate (5-MTHF) – in this form folates are used by our body. Folic acid and folates are different forms of B9. Folic acid is a synthetic form of vitamin B9, whereas folate is, as already mentioned, a natural form found in food. In various sources these names are used interchangeably, although the differences between them (especially in their metabolism are significant), so the determination of vitamin B9 – folic acid is incorrect. The synthetic form of vitamin B9 – folic acid is widely used in dietary supplements and added to food products.
Vitamin B9 is a compound that can not be synthesized by humans and must be supplied with food. It performs a number of important functions in the body, and its nutritional deficiencies are one of the most common avitaminoz. Vitamin B9 has a special role in the period preceding pregnancy and in the first trimester of its duration. For this reason, the appropriate amount of it in the diet of women of childbearing age is particularly important. What is the role of vitamin B9 in the body, what are the effects of its deficiency and when and in what form should supplementation be used?
Features in the body of vitamin B9
Vitamin B9 is involved in the synthesis of phospholipids, protein methylation and DNA structure, protein synthesis, amino acid transformation and hematopoietic processes (formation of red blood cells, is therefore an antianemic agent), participates in the formation of gastric juice, ensures the smooth operation of the liver, stomach and intestines, protects the body against cancer. A low level of vitamin B9 translates into a high level of harmful amino acid homocysteine, which adversely affects the cardiovascular system. One of the most important functions of vitamin B9 is to reduce the risk of birth defects in fetuses that are associated with abnormal neural tube closure.
Sources in vitamin B9 food
Folates are found in both plant and animal products. The largest amount is contained in leaf vegetables (broccoli, lettuce, Brussels sprouts, spinach, kale, kale), wheat germ, bran, asparagus, baker’s yeast, legume seeds. Among the animal products, the liver and egg yolks are particularly rich in folate.
Daily requirement for vitamin B9 (recommended level of consumption) for various population groups
Demand for vitamin B9 according to Dietary Reference Intakes determined by the American National Academy of Sciences, Food and Nutrition Board.
* 1 Recommended daily intake (RDA) – a value that satisfies the needs of more than 97.5% of the healthy population in each age group, both sexes. This value is estimated by statistical methods.
* 2 Maximum level of intake (UL) – a value that does not cause harmful effects in healthy people, as stated in the studies under medical supervision.
The effects of vitamin B9 deficiency
Vitamin B9 deficiency contributes to abnormal fetal development, especially to the formation of neural tube defects and disorders of the proper functioning of the nervous system. Defects of the central nervous system include, but are not limited to, a hernia of the brain and spinal cord, anencephaly or spina bifurcation and spinal cavity. Too low supply of this vitamin along with the diet may also result in megaloblastic anemia (mimetic anemia), low birth weight of newborns, miscarriages and premature births. The studies also showed the influence of insufficient vitamin B9 intake on the increased risk of atherosclerotic and cancerous changes. Girls with puberty, women of childbearing age and pregnant women are particularly at risk for vitamin B9 deficiency.
(Un) stability and sensitivity of folates derived from food
Folates are unstable and sensitive to environmental factors such as high temperature (cooking reduces the content of folates by 40-70%), light, oxygen, acidity of the environment. When cooking, for example, spinach, the folate content in it decreases by half. Storage of food products causes the oxidation of vitamins to the less-available derivatives thereof. Technological processing of food products (eg peeling, slicing) also contributes to the reduction of folate content in food. The bioavailability of folate from food can also be limited by many factors such as alcohol, smoking, some medications, contraceptives or diseases of the digestive tract, eg celiac disease. Deficiencies of iron and vitamin C impair the use of folates by the body.
Why is vitamin B9 particularly important in the diet of women?
Vitamin B9 is necessary for the proper functioning and growth of all cells. Participates in the production of red blood cells (in the circulatory system) and the brain and spinal cord (in the nervous system). The deficiency of vitamin B9 during the development of the most important systems in the fetus can cause defects in the central nervous system of the fetus. Insufficient amount of vitamin B9 during pregnancy also poses a threat of spontaneous abortions and births of a child with low birth weight.
When and why is B9 supplementation recommended?
The high mortality rate, which is caused by congenital malformations and other numerous effects of vitamin B9 deficiency, led to the establishment in 1997 of the Prevention of Wolves in the Nerve Tube. The program aims to raise the awareness and knowledge of women about the importance of vitamin B9 and the effects of its deficiency. Numerous studies have shown that supplementation with B9 vitamin reduces the risk of neural tube defects in the fetus by as much as 70%. The mortality rate for this reason in Poland is the highest in Europe, and the incidence rate is 2.68 per 1,000 births. The Preventive Tolerance Defect Prevention Program provides recommendations on the use of supplementation by women planning pregnancy, women of childbearing age and sexually active women and pregnant women. It is recommended to use 0.4 mg (400 μg) of folic acid daily by women of childbearing age, especially for at least 3 months before the planned pregnancy and the first trimester. It is important to properly saturate the body with vitamin B9 before becoming pregnant, because in the first weeks of fertilization may lead to inadequate processes of fetal brain development. It is worth noting that the B9 reserves in the body are low, and in the period of increased demand, they may be exhausted after just 3 months. Women with an increased risk (that is, women who have had a child with a neural tube defect) are advised to take a tenfold higher dose of vitamin B9, or 4 mg (4000 μg).