Folic acid, also known as vitamin B9, is a nutrient that participates in various functions in the body, such as:
- Maintain brain health, preventing problems such as depression;
- Participate in the formation of the nervous system of the fetus during pregnancy;
- Strengthen the immune system;
- Prevent anemia, by stimulating the formation of blood cells;
- Prevent colon cancer by preventing changes in the cells' DNA;
- Prevent heart disease and stroke by reducing homocysteine and maintaining blood vessel health;
- Control the evolution of vitiligo.
To prevent malformations in the fetus such as spina bifida, women planning to become pregnant or who are pregnant should take supplements in folic acid capsules according to medical advice. See How to take folic acid for pregnancy.
Foods rich in folic acid
The following table shows foods rich in folic acid and the amount of this vitamin in 100 g of each food.
| Food (100 g) | B.C. Folic acid (mcg) | Food (100 g) | B.C. Folic acid (mcg) |
| Spinach | 150 | Raw broccoli | 90 |
| Corn Flakes | 167 | Kale butter | 78 |
| Fried cow liver | 350 | Raw mushroom | 44 |
| Bean | 210 | Mango | 36 |
| Parsley | 170 | Tomato | 17 |
| Asparagus | 155 | Orange | 31 |
| Brussels sprouts | 110 | Oat flakes | 56 |
| Baked Beans | 210 | Whole Wheat Bread | 31 |
In addition to these foods, wheat flour marketed in Brazil is fortified with folic acid, and therefore products such as bread, biscuit and pasta are also sources of this nutrient.
Recommended quantity
The recommended amount of folic acid per day varies by age, as shown in the following table:
| Age | Quantity of Folic Acid |
| 0 to 6 months | 65 mcg |
| 7 to 12 months | 80 mcg |
| 1 to 3 years | 150 mcg |
| 4 to 8 years | 200 mcg |
| 9 to 13 years | 300 mcg |
| 14 years and over | 400 mcg |
| Pregnant women | 600 mcg |
| Women who breastfeed | 500 mcg |
Folic acid supplementation should always be done under medical guidance, and is usually recommended in cases of vitamin A deficiency, anemia, or for pregnant women.
Side effects and contraindications of drug supplementation
Folic acid is a water-soluble vitamin and therefore its excess is easily eliminated through the urine. However, the use of folic acid supplements without medical advice or in concentrations above 5000 mcg, which is the recommended daily dose, can cause problems such as stomach pain, nausea, skin itching or masking of vitamin B12 deficiency anemia, for example, which is the case of pernicious anemia.
Folic acid supplementation should also be guided by the physician in the elderly or strict vegetarians, as there is a greater chance of vitamin B12 deficiency due to situations related to the decrease in the absorption capacity of this vitamin or to the diet. In addition, in cases of use of medicines for seizures and rheumatism, the folic acid supplement should only be consumed according to medical advice.
See an example folic acid supplement and how to take it here.
