What is folic acid?
An essential vitamin for the growth of our cells
Folic acid, which is also known as vitamin B9, is essential for the growth of our cells. It is involved in the synthesis of the components of DNA.
It plays an important role in cell renewal, in the production of red blood cells, and it contributes to the synthesis of neurotransmitters, chemical messengers ensuring the transmission of nervous information.
Common deficiencies
A folic acid deficiency is observed in cases of insufficient intake, caused by a poor intestinal absorption (IBD: chronic inflammatory bowel diseases, celiac disease…), or if needs are increased (pregnancy, alcoholism).
In these cases, even a balanced diet cannot correct the deficiency.
A hereditary malabsorption may also occur, a rare genetic disorder affecting folic acid transport.
What are its benefits?
A vitamin essential during pregnancy
Folic acid is now routinely prescribed by physicians from preconception, because it is essential for the development of the fetus.
When the embryo’s central nervous system is forming, folic acid must be sufficiently present because it contributes to the proper closure of the neural tube (the precursor of the future spinal cord), as this article notes.
An abnormality of this tube can cause a very severe disability at birth.
This analysis highlights that a folic acid deficiency during pregnancy can also increase the risk of fetal growth restriction, preterm birth, and neonatal mortality related to neural tube defects.
An antioxidant action
Folic acid, or vitamin B9, is part of the family of vitamins called “folates”. They are essential for the synthesis, repair, and proper functioning of the genetic material.
It helps prevent the increase of an oxidizing molecule called homocysteine, which can damage DNA.
This amino acid is a true factor in the aging of our body : in case of a vitamin B9 deficiency, there is an accumulation of homocysteine in the blood.
The risk of aging in our body accelerates, as does the risk of developing degenerative diseases.
Thus, a clinical trial of 450 participants concluded that taking folic acid for 8 weeks is beneficial to protect the body against oxidative damage to DNA.
An effect on the nervous systemx
The level of vitamin B9 in the brain is particularly high.
The role of this vitamin in the nervous system is not yet well defined, but its action on amino acid metabolism and on DNA synthesis is certainly essential.
Numerous studies have observed an association between folate deficiency and the occurrence of neurological conditions: dementia, schizophrenia-like syndrome, insomnia, irritability, forgetfulness, depression…
A trial of 46 patients with severe depression revealed that half of them (52%) had a significant reduction in folic acid.
Another trial involving 127 patients taking an antidepressant was conducted: in addition to their treatment, they received either a placebo (no therapeutic effect) or 500 mg of folic acid.
The antidepressant effect of the medication was enhanced by taking folic acid, with a significant improvement in depressive symptoms.
In addition, a review of studies shows that a low folic acid level is a risk factor for dementia and could increase the risk of developing Alzheimer’s. A recent analysis indicates that an adequate intake is a protective factor.
Finally, this study indicates that long-term supplementation appears to improve cognitive function in healthy older adults.
A contradictory effect on cancer
Many studies are underway on a possible link between folic acid and the occurrence of cancer. Indeed, it could increase the risk of developing certain cancers and decrease the risk of others.
A higher folate level would significantly reduce the risk of lung cancer, as shown by this study, and appears to protect against pancreatic cancer (only in women).
Some studies, but not all, indicate that folic acid supplementation protects against the development of colorectal cancer.
This comprehensive analysis reports that folate intake may be associated with a reduced risk of colon cancer, although there is evidence of a possible increase in tumor growth with supplementation, most often at doses higher than physiological levels.
Since the results of current studies are not unanimous, I recommend that you follow the recommended nutritional values when supplementing, as well as the duration of use, after consulting a knowledgeable healthcare professional.
What are the food sources of folic acid?
The brewer’s yeast is the most concentrated dietary source of vitamin B9.
They are then found in leafy vegetables (watercress, lamb’s lettuce, spinach, white cabbage, Swiss chard) and green (broccoli, zucchini, green bean, pea).
They are also found in red fruits (cherries, strawberries, raspberries), in legumes (chickpeas, red and white beans, lentils), and in red meat. Offal (such as liver) contains them in particular.
However, up to 70% of folates can be lost during cooking.
A diet rich in folic acid is particularly important before conception and throughout pregnancy.
In what form?
In capsules
It is indeed the folic acid molecule that is found in dietary supplements, because the natural folates in foods are unstable during manufacturing.
Capsules contain a powder form.
Manufacturing is easy, so the cost is reasonable, and the dosage is precise. The other advantage is ease of transport.
The taste is masked, the odors not completely. Depending on capsule size, it can be difficult to swallow the hard capsule and I recommend drinking a large glass of water to help with swallowing.
In capsules
The so-called “soft” capsules contain liquid or pasty forms, notably vegetable oils.
They have many advantages: the dosage is precise, the unpleasant taste can be hidden.
These forms often contain several active ingredients. In addition, the capsule is quickly opened in the digestive tract, so absorption is improved.
However, they have disadvantages related to their storage: the capsules are more sensitive to heat and to moisture.
In tablets
Tablets are the least expensive form. Easier to swallow than capsules, they are generally properly dosed.
They have better shelf life and are less fragile.
What criteria should be considered?
1. Different forms of folic acid
Folic acid does not exist in a natural state: the folates present in our body are in different forms, including the form methyl-tetrahydrofolates, or methylTHF.
Indeed, some folates are absorbed through the diet and undergo a molecular modification (called methylation) in the intestine to then be converted into methylTHF and folic acid.
You will therefore find dietary supplements on the market that contain folic acid or methylTHF.
Part of the population assimilates it poorly: the liver can only metabolize a certain amount of folic acid.
And the unused portion can remain in the blood and could increase the risk of cancer when taken long-term.
Moreover, the liver enzyme involved may undergo a genetic modification that disrupts this conversion to methylTHF.
In people with this mutation, folic acid supplementation can be ineffective!
I therefore particularly recommend choosing a product containing a “methyl” form of vitamin B9 if you wish to boost your folate intake.
Nevertheless, it remains a widely used form, stable, and more affordable in terms of cost.
2. The origin
Folic acid is therefore not a ‘true’ vitamin B9, because this form is not natural. Its health effects do not replace those of natural vitamin B9 but it remains a good supplement.
Although methylTHF occurs naturally, the products offered in dietary supplements are not more natural than folic acid, because they are produced by chemical synthesis.
So, no naturally occurring folic acid is found in dietary supplements.
3. Bioavailability
Folic acid is more stable than the methylTHF form.
To stabilize the latter form and thus achieve optimal absorption, some laboratories couple the active ingredient with glucosamine.
This natural molecule is present in various tissues of the human body, and is used in its salt form.
This combination allows the protection, transport, and absorption of folate to its site of action.
4. Dosage of folic acid
The recommended daily intake of folates is 300 micrograms for women, and 330 micrograms for men.
Recommended intakes are also determined on a case-by-case basis, to prevent cardiovascular and cancer risks (notably colon cancer), and the risk of deficiencies during pregnancy.
During supplementation, in cases of anemia, the doctor generally prescribes between 5 and 15 mg per day depending on the situation.
For women planning pregnancy, the recommendations are 400 micrograms of folic acid per day, one month before conception and up to three months after it.
Supplementation is routinely prescribed by the doctor or the gynecologist.
For women with a history of pregnancies affected by neural tube defects (such as spina bifida), or in cases of diabetes or antiepileptic treatment, the doctor prescribes a dose of 5 milligrams per day.
Is there a danger in taking folic acid?
Folic acid supplementation is particularly recommended during pregnancy, when requirements double.
Folic acid can interact with certain medications, notably with antiepileptic drugs.
Folates also interfere with Methotrexate, a drug used in chemotherapy and for inflammatory conditions (psoriasis, severe dermatitis, rheumatoid arthritis, etc.).
Taking folates counteracts the action of the medication.
Finally, supplementation can mask the symptoms of a vitamin B12 deficiency, which can ultimately lead to neurological damage.
It is essential not to supplement long-term without the advice of your pharmacist or your doctor.
To summarize
To make sure you choose folic acid of good quality, check:
- Form : choose a methyl-based supplement;
- Origin : there is no natural form in dietary supplements;
- Bioavailability: combined with glucosamine, the methyl form is better absorbed by the body ;
- Dosage: for women planning a pregnancy, the recommendations are 400 micrograms of folic acid per day, one month before conception, and up to three months after it.
