Folic acid is essential for every cell in the body.
Folic acid is a synthetic form of vitamin B9, or folate. It is involved in the synthesis of components from which the body builds DNA chains. If there is not enough folic acid, the cell cannot divide and grow normally.
Folates are especially needed by tissues whose cells divide constantly and quickly: blood, mucous membranes, skin, immune system, and intestinal wall.
Vitamin B9 is involved in the metabolism of homocysteine, an amino acid whose excess is associated with the risk of atherosclerosis and stroke. Without vitamin B9, homocysteine does not convert into methionine, another important amino acid, and begins to accumulate in the blood, damaging blood vessels.
Vitamin B9 also participates in the synthesis of neurotransmitters, substances that transmit signals from one nerve cell to another. It affects cognitive functions and is involved in mood regulation.
The body of an adult contains about 15–30 mg of folate, and half of this reserve is stored in the liver. If a person does not receive enough folic acid from food, a deficiency can develop within 2–4 weeks.
Folic acid deficiency increases the risk of serious diseases
Folic acid deficiency does not immediately manifest itself with obvious symptoms. But its consequences are dangerous: due to folate deficiency, normal biochemical processes in the body are disrupted. Damage accumulates, which, over time, can lead to the development of pathology.
- Hematopoiesis disorder — megaloblastic anemia. One of the first symptoms of folate deficiency. Red blood cells become too large and do not mature fully, so they cannot effectively transport oxygen. As a result, a person feels weak, tired, short of breath, dizzy, and has decreased concentration. At risk are the elderly, people with low gastric acidity, malabsorption syndrome, vegans, and those who have had part of their stomach removed.
- Increased risk of stroke, thrombosis, and atherosclerosis. Against the background of folate deficiency, unprocessed homocysteine can cause damage to the vascular endothelium, increase inflammation activity, and provoke oxidative stress. Sometimes this leads to the formation of blood clots. Studies show that taking folic acid can reduce the risk of stroke by 21–25%, especially in regions with low folate intake.
- Risk of cancer. The less folate in the body, the higher the risk of errors in reproducing the DNA chain, which can lead to the development of malignant tumors. Researchers have proven that low levels of vitamin B9 are associated with the risk of developing cancer of the gastrointestinal mucosa.
- Mental disorders and cognitive impairment. Folic acid deficiency may be associated with depression, irritability, and apathy. In older people, it is associated with an increased risk of dementia and cognitive decline. Those at risk include those with alcohol dependence, celiac disease, inflammatory bowel disease, and those taking methotrexate and anticonvulsants.
During pregnancy, the need for folic acid increases several times.
During pregnancy, especially in the first trimester, the embryo’s cells actively divide and grow rapidly. During this period, folic acid is one of the most important vitamins, without which the normal development and formation of vital organs of the fetus is impossible.
During the first 28 days, the embryo develops a neural tube, which will later develop into the spinal cord and brain. If a woman’s body lacks folates at this point, the risk of serious defects increases, including spina bifida. This abnormality may remain asymptomatic, or it may manifest itself in severe abnormalities, such as a herniated disc.
Often, such disorders occur even before a woman finds out about pregnancy. Therefore, doctors recommend starting to take folic acid at the preparation stage, 3-6 months before the planned conception.
In addition, folic acid can reduce the risk of premature birth, gestational hypertension and preeclampsia, low birth weight, heart defects and other congenital anomalies. There is evidence that sufficient levels of folates in the mother’s body reduce the risk of leukemia and other malignant diseases in the child.
Taking folic acid may mask a vitamin B12 deficiency
Both folic acid and vitamin B12 (cyanocobalamin) are important for the proper functioning of bone marrow and the synthesis of blood cells, and a deficiency of these substances leads to megaloblastic anemia. However, taking only folates in high doses is enough to normalize hemoglobin levels and eliminate the symptoms of hematopoiesis disorders, but at the same time, it can mask a deficiency of B12.
This is unsafe: due to a lack of cyanocobalamin, nervous tissue can be destroyed. The spinal cord suffers first. Subacute combined degeneration develops – a severe and potentially irreversible condition in which motor and sensory nerve fibers are damaged. Drowsiness, weakness, irritability, tingling and numbness in the hands and feet, and stiffness of movement appear.
It is because of the risk of masking a B12 deficiency that many multivitamins and fortified foods contain both vitamins—folate and cyanocobalamin—in recommended amounts. For example, in the United States, manufacturers are required to list the amount of folate on the label and often add 100% of the daily value of B12 to prevent possible imbalances.
Too much folic acid can be harmful
Most folates that enter the body from outside are excreted in the urine. However, with prolonged intake of folic acid in doses above 1000 mg per day, undesirable effects may develop:
- stimulation of the growth of precancerous and cancerous cells that have already appeared in the body;
- nausea;
- vomit;
- bitterness in the mouth;
- irritability, emotional lability, and sleep disturbances.
There is little reliable data on the toxicity of folic acid. But experts emphasize that it is necessary to take it strictly according to the indications and not to exceed the doses prescribed by the doctor.
Thermal processing of foods reduces the amount of folate in them
Folate from foods is a polyglutamate form of the vitamin. Before absorption in the intestine, they are processed and lose about half of their nutritional value: their bioavailability is, on average, about 50%. In comparison, up to 85–100% of synthetic folic acid is absorbed from supplements or fortified foods.
However, it is important to include natural foods high in folate in your diet:
- Beef liver (100 g) – 215 mcg.
- Cooked spinach (½ cup) – 131 mcg.
- Cooked black beans (½ cup) – 105 mcg.
- Cooked asparagus (4 stalks) – 89 mcg.
- Avocado (½ cup) – 59 mcg.
- Whole grain bread (1 slice) – 50 mcg.
- Orange (1 small) – 29 mcg.
- Egg (1 pc..) – 22 mcg.
- Banana – 24 mcg.
During heat treatment, the bioavailability of folates from food decreases even more – for example, during long cooking, up to 50-70% of the vitamin is destroyed. To preserve it, it is better to cook foods in gentle ways: steam, simmer, and add greens to dishes at the end of cooking. For example, spinach boiled for 10 minutes loses up to half of the folate compared to the same amount in raw form.
Raw vegetables and salads are a great way to preserve the maximum amount of vitamins. It is also useful to combine folate-containing foods with sources of vitamin C, which improves the absorption of vitamin B9, and with proteins, they participate in the synthesis of enzymes necessary for folate metabolism.