Vitamin B9: role of folic acid, risk of deficiency?

Vitamin B9 or folic acid plays several major roles in the body: it contributes to the normal blood function and participates in mechanisms of cell division and growth (hence its importance during pregnancy). She could also have protective effects against Alzheimer’s disease, cardiovascular diseases and certain cancers. However, even with a balanced diet rich in vitamin B9, the deficiency is commonthis because this vitamin is very fragile and cooking destroys it.

What is vitamin B9 used for?

There vitamin B9 is a B group vitamin that plays several essential roles in our body.

► “It enters in particular into the mechanism which is used to manufacture red blood cells“, informs Dr Stéphane Bounan, gynecologist-obstetrician, head of the maternity department at Delafontaine hospital (Saint-Denis).

► It has a role in the production of white blood cells.

► She participates in cellular mechanism, in particular in the production of the central nervous system in the embryo. “Between the 14th and 30th day of pregnancy, the embryo forms the primordial elements of its central nervous system.“, specifies the specialist.

► It plays a role in the skin renewal and the wall of the intestine.

Many men and women are deficient in vitamin B9

What are the symptoms of folic acid deficiency?

A folate deficiency corresponds to a folic acid deficiency, that is to say in vitamin B9. Even with a balanced diet rich in vitamin B9, deficiency is common, because this vitamin is very fragile and cooking destroys it. “In the general population, blood levels of vitamin B9 are not very high and many men and women are deficient in vitamin B9“, underlines the doctor. “A lack of vitamin B9 can cause anemia” he continues. This lack leads to a slowdown in the multiplication of cells, particularly cells with a high renewal rate such as blood cells (red and white blood cells), those of the intestine, the liver, and the skin. THE signs of this hypovitaminosis are therefore anemia, digestive and neurological disorders and mucosal damage (gums For example).

“In pregnant women, if by the time the embryo forms its central nervous system it is lacking in vitamin B9 because there is not enough in the maternal blood, this can lead to central nervous system abnormalities. The best known of the anomalies of closure of the neural tube (outline of the future spinal cord) is the Spina Bifida“ says Dr Stéphane Bounan. “The spinal cord remains open with unprotected nerve fibers. This can lead to very severe disability at birth” he explains. Folic acid deficiency during pregnancy can also be the cause of fetal growth retardation in utero (IUGR), increased risk of prematurity.

In which foods can you find vitamin B9?

Folic acid is present in particular in:

• Leafy green vegetables : spinach, watercress, dandelion, lamb’s lettuce, lettuce, endive, cabbage, leeks…
• Fruits like chestnuts, melons, nuts, bananas, red fruits, dates or kiwi…
• Legumes like chickpeas, lentils…
• Other vegetables like green beans, radishes, artichokes, zucchini, avocados, onions, peppers…

Please note that this vitamin is fragile: heatboiling and light destroy it in large quantities. Also, to preserve the folate content of foods, particularly fresh vegetables, it is recommended to keep them cool, consume them quickly and avoid long cooking in water.

Can you get vitamin B9 without a prescription?

Vitamin B9 is available in pharmacy without prescription but it is recommended to consult a doctor before self-medicating. People with a deficiency can be prescribed medications containing vitamin B9, as can women before and during the first trimester of pregnancy. The doses are adapted according to the level of deficiency.

Can we measure vitamin B9 in the blood?

It is possible to test the plasma folate level (in the blood) to see if there is a deficiency. A blood test for vitamin B9 can be prescribed for patients with symptoms such as anemia, digestive disorders, neurological disorders or memory problems in the elderly. “Vitamin B9 blood testing is not done systematically in pregnant women. Blood tests are carried out if the woman has anemia, in order to check for a deficiency in iron, vitamin B9 or vitamin B12.“, informs Dr. Stéphane Bounan.

What are normal levels of vitamin B9 in the blood?

Normal values ​​should be between 11 and 34 nmol/l, i.e. 5 – 15 µg/L in serum and between 340 and 1000 nmol/l, i.e. 150 – 450 µg/L, in red blood cells. Please note, the standards differ depending on the laboratory analysis techniques.

However, the blood level of vitamin B9 may decrease in the event of:

• permanent stress,
• prolonged fever,
• stomach surgery,
• taking oral contraceptives,
• insufficient nutritional intake,
• excessive consumption of tea or coffee,
• malabsorption (celiac disease, intestinal disease, certain parasitic infections, alcoholism),
• increased needs (pregnancy, breastfeeding, acute infections, certain cancers, dialysis, congenital disorders and taking certain medications including certain antibiotics and anticonvulsants).

Why should you take vitamin B9 when you are pregnant?

Women should start taking vitamin B9 as soon as they start planning to conceive a baby. “In France, as soon as we learn that a woman wants to become pregnant, we prescribe vitamin B9 tablets to increase her reserves in the blood. Ideally, you should start several months before pregnancy, and at least 1 month before. Thus, the level of vitamin B9 in the blood will be good at the start of pregnancy“, informs Dr. Stéphane Bounan.

Taking vitamin B9 before the start of pregnancy helps avoid a deficiency in the blood which could lead to central nervous system malformations during the formation of the embryo. “Studies show that it reduces the risk of central nervous system abnormalities by two thirds.l”, he explains. This vitamin B9 supplementation is continued until the 12th week of amenorrhea.

Thanks to Dr Stéphane Bounan, obstetrician-gynecologist, head of the maternity department at Delafontaine hospital (Saint-Denis).