Generality
What is folic acid?
Folic acid is a water-soluble vitamin of group B; especially in the United Kingdom and the USA, the group of all related molecules (called " folates ") is also called vitamin B9 .
Being more or less thermolabile (the susceptibility to heat varies according to the chemical form) and unstable (it suffers light, oxidation, etc.), this micronutrient is often degraded by cooking and during storage.
Since during pregnancy the need for folic acid increases significantly (so much so that it is often insufficient in terms of diet) the foods that contain it should be eaten mainly raw and fresh. In this case, for hygienic reasons, during pregnancy it is strictly advisable to carry out a thorough chemical disinfection (by means of chlorine and / or ammonium based disinfectants).
Folic acid and folate: differences
Although the two terms are often used as synonyms, folic acid and folate are not exactly the same thing. We try to understand better why.
Folic acid
Folic acid is the most oxidized and stable form of the vitamin; rare in common foods, it is synthesized in the laboratory and intended for the fortification of food products and the preparation of vitamin supplements, including those recommended during pregnancy.
folate
Folati, on the other hand, is a generic term referring to all compounds with B9 vitamin activity, of precursor or vitaminosimile type (folic acid, folinic acid, tetrahydrofolate, etc.); these substances have an excellent bioavailability, superimposable to that of folic acid, but they are easily denaturable with heat, light, cooking and preservation.
To cover the daily need for folic acid for pregnant women, in addition to the dietary intake, also contributes a small share of folate produced by intestinal bacterial flora.
Functions
General functions of folic acid
Folic acid is used by the body for cellular reproduction; it intervenes in the synthesis of DNA, proteins and hemoglobin (it participates in erythropoiesis, the process of formation of red blood cells), so that its deficiency is associated with an anemic form called megaloblastic.
Why is folic acid important during pregnancy?
From the earliest stages of pregnancy, the product of conception (first zygote, then embryo, then fetus) becomes a huge consumer of folate, due to the intense processes of cell proliferation and differentiation. Also the increase of maternal erythropoiesis contributes to increase the folic acid needs during pregnancy (in view of the delivery the volume will be increased by 30-50% compared to the pregravidici values).
Food
Where is folic acid located?
Folic acid is abundant in green leafy vegetables, artichokes, turnips, brewer's yeast, cereals - especially if they are whole - in legumes, egg yolk, liver, kiwis and strawberries (see article related to: folate in food).
Food sources of folic acid for pregnancy
All these foods rich in folic acid are indicated for consumption during pregnancy. For hygienic reasons, they are more recommended:
- CHEMICAL DISINFECTED fruits and vegetables (for example with amuchina)
- Fruit and vegetables to consume PEEL.
| Good dietary sources of folic acid | |
| Foods that can help you get more folic acid in your diet include: | |
| 400 μg | Breakfast cereals, fortified with 100% of the Daily Value FDA, 50 g |
| 215 μg | Beef liver, cooked, 100 g |
| 179 μg | Lentils, ripe, cooked, boiled, 100 g |
| 115 μg | Spinach, frozen, cooked, boiled, 100 g |
| 110 μg | Egg noodles, enriched, cooked, 100 g |
| 100 μg | Breakfast cereals, fortified with 25% of the Daily FDA Value, 50 g |
| 90 μg | Beans, boiled, 100 cup |
RECOMMENDED food sources of folic acid for pregnancy
In pregnancy it is advisable to avoid ready-made fruit and vegetables at the bar, in vending machines or in gastronomy, due to the danger of contracting toxoplasmosis or some foodborne illness such as listeriosis.
Despite the nutritional richness of folic acid, iron, etc., excessive consumption of the liver as a food is also DISABLED during pregnancy. This recommendation is justifiable by the fact that this organ is a kind of "filter", responsible for the metabolization of toxic substances (which tend to accumulate inside it). Moreover, it contains very high levels of vitamin A which, if in excess, exerts a very serious (teratogenic) toxic effect for the unborn child.
Food Impoverishment
What factors decrease the concentration of folic acid in food?
Like most water-soluble vitamins, folic acid is largely denatured during food processing. Food preservation and cooking, for example, destroy up to 95% of the original folate heritage; a green leafy vegetable stored at room temperature for three days, on the other hand, sees this availability reduced to 70%.
Furthermore, the interaction of the various food substances - coming from the same food or from foods consumed in the same meal - can reduce the bioavailability of food folates up to 50%; consequently, it is believed that only half of the amount ingested is actually absorbed.
requirement
Folic acid requirement in the population and in pregnancy
The need for folic acid is not the same for the entire general population. It grows progressively according to age and reaches the highest levels during pregnancy and lactation; as we shall see, there are also special conditions that contribute to increasing the physiological demand.
In the table below we summarize the need for folic acid at different stages of life.
| Age | Need for Folic Acid |
| 6-12 months | 110 μg |
| 1-3 years | 140 μg |
| 4-6 years | 170 μg |
| 7-10 years | 250 μg |
| 11-14 years | 350 μg |
| 15-17 years | 400 μg |
| 18-29 years old | 400 μg |
| 30-59 years | 400 μg |
| 60-74 years | 400 μg |
| ≥ 75 | 400 μg |
| PREGNANCY | 600 μg |
| FEEDING TIME | 500 μg |
What factors increase the need for folic acid?
The need for folic acid can significantly increase:
- Cigarette smoke (to be avoided absolutely during pregnancy)
- Ethyl alcohol (to be avoided absolutely during pregnancy)
- Some medicines
- Certain pathological conditions (intestinal diseases due to malabsorption etc.) or genetic anomalies (metabolic alterations, etc.).
Which drugs increase the need for folic acid?
Among the drugs we remember the contraceptive pill, whose suspension in the search for a pregnancy can expose the woman to a deficiency precisely in the most delicate period, which as we will see later on is precisely the one adjacent to conception.
Among the medicines capable of interfering with the metabolism of folic acid, we also mention the antiblastic chemotherapy (such as methotrexate) and anticonvulsants (such as valproic acid, diphenylhydantoin, aminopterin and carbamazepine).
Genetic differences that increase the need for folic acid
As explained so far, the best way to cover the daily requirement of folic acid would be to consume raw fruits and vegetables, as fresh as possible. We specify once again that during pregnancy it is a good idea to wash and disinfect raw vegetables with particular care.
shortage
Lack of folic acid and risks to the health of the unborn child
A lack of folic acid during the first stages of gestation increases the risk of neonatal malformations, in particular those affecting the neural tube (DTN). This term indicates a heterogeneous group of malformations, accumulated by an anomalous closure of the neural tube during the fourth week of embryonic development (the neural tube is the structure from which the central nervous system originates, therefore the brain and spinal cord ).
The most frequent neural tube defects are anencephaly (50% of cases) and defects of closure of the spine (spina bifida, 40% of cases) and cranial vault (encephalocele, 10% of cases). Unlike the former, the latter are often compatible with life, but are associated with neurological deficits and physical malformations of varying degrees (often severe).
The overall incidence of NTDs in Italy is low, but not negligible (0.7-1 ‰ - 0.7 -1 per thousand).
Integration
Folic acid supplementation could play an important preventive role against preeclampsia and eclampsia, recurrent spontaneous abortion, placental abruption, fetal malformations, growth retardation, low birth weight and intrauterine death. Let's go into more detail.
Importance of folic acid supplementation for the unborn child
Integration with folic acid does not eliminate the risk that the product of conception develops defects in the closure of the neural tube, but reduces it significantly; broadly decreases it by 30-40% at a dosage of 0.4 mcg / day, up to 70-80% at doses of 4-5 mg / day. Furthermore, in various studies it has been shown that folic acid is able to prevent the appearance of other congenital malformations, including cardiopathies, cleft lip and palate, urinary tract defects, hypo-agenesis of the limbs, omphalocele and anal atresia .
Importance of folic acid supplementation for pregnant women
The preventive activity of folic acid against hyperhomocysteinemia helps to reduce the mother's cardiovascular risk, so much so that a preventive role against pregnancy hypertension and its complications has been hypothesized.
dosage
How much folic acid and for how long?
To prevent neural tube closure defects, every woman should take 400 µg (400 mcg = 0.4 mg) of folic acid a day in the form of specific supplements; this dosage corresponds to about 65% of the pregnant woman's daily requirement. Note : in the USA, from the fourth to the ninth month of pregnancy, we recommend 600 µg of folic acid a day.
As mentioned in the previous paragraphs, it is essential that this assumption begins a month before conception (to increase reserves) and continues throughout the first trimester of pregnancy. This particular dosage of folic acid is recommended to ALL people of childbearing age who do not apply effective contraceptive measures.
Doses higher than 0.4 mg of folic acid per day can be specifically recommended only to women who have already had a child with neural tube closure defects, or with familiarity with this type of malformation. Recent scientific evidence, in fact, suggests that an increase in dosages up to 5 mg per day has more incisive effects in reducing the risk of NTD. Particular attention to the correct vitamin supplementation scheme should therefore be placed in women considered at risk (malabsorption problems - such as celiac disease or Crohn's disease - use of drugs that can interfere with folic acid metabolism, specific enzymatic deficits etc.) .
In pregnant women not at risk, the use of dosages equal to 0.4 mg / day - with the recommendation not to exceed the mg / day - arises from the fear of hypothetical fetal risks linked to the high blood level of synthetic folic acid .
Under medical advice, folic acid can also be taken as a multivitamin supplement during pregnancy; in this regard it is recommended to choose a product free of vitamin A (retinol), since excessive doses of this vitamin can produce teratogenic effects (induce fetal malformations); in particular, the introduction of vitamin A in the form of multivitamin supplements containing retinol should not exceed 3, 000-5, 000 IU / di. There do not seem to be any particular risks when vitamin A is taken in the form of plant precursors (carotenoids).
Given that a good percentage of pregnancies is in no way planned by parents, many countries have undertaken campaigns to fortify flour and cereals with folic acid, in order to increase the daily intake of the vitamin.
