Water-soluble vitamins Part III: Folic acid in focus
Another popular representative of the water-soluble vitamins is folic acid. Strictly speaking, this substance belongs to the group of B vitamins, according to its designation as vitamin B9. However, since the term folic acid is used in common parlance and this vitamin plays a special role in general medicine, we will discuss the dosage, biochemical effects and special features of this substance in detail below.
Five facts at a glance
1. The daily folic acid dose for men and women is 300 micrograms.
2. Women who want to become pregnant or are already pregnant should take a higher dose (400 or 550 micrograms per day). The aim is to prevent various malformations in the child.
3. Even though vitamin deficiencies are rare in our latitudes, folic acid deficiency is comparatively common.
4. Folic acid plays a central role in nucleic acid and amino acid metabolism. Consequently, this vitamin is indispensable for the formation of new cells.
5. A deficiency of folic acid results in a variety of symptoms. In particular, the clinical picture of megaloblastic anaemia can usually be observed
Ensure folic acid intake — it is not uncommon to have a deficiency
Since specific vitamin deficiencies are the exception in our latitudes, a deficiency in the body’s supply of folic acid is comparatively common. According to the German Nutrition Society, adults, both men and women, need a daily intake of 300 micrograms. If we look at the actual supply situation, it is noticeable that a large proportion of people in this country are only scratching the mark of the daily requirement. It is therefore not uncommon for general practitioners to see themselves obliged to clarify a sufficient folic acid level in the case of various symptoms. It should be noted that folic acid is stored in the liver as a water-soluble vitamin with about 10 mg. This supply lasts for several months even if the folic acid supply is insufficient. Certain vegetables such as spinach and beans are particularly rich in folic acid. To cover the daily requirement of 300 micrograms, for example, about 300 grams of green vegetables would have to be consumed.
Pregnant women should be especially careful about the amount of folic acid they need.
The folic acid requirement almost doubles when women become pregnant. The German Society for Nutrition, however, recommends a daily intake of 550 micrograms. Based on scientific findings, women who “want to become pregnant or could become pregnant” are already recommended an amount of 400 micrograms per day. Especially during pregnancy, various disadvantages have been observed with a folic acid deficiency. These included mainly miscarriages, malformations and developmental disorders of the child. In the USA, folic acid is added to cereals to prevent congenital malformations.
The central task of folic acid is amino acid and nucleic acid metabolism.
Folic acid plays an important role in amino acid and nucleic acid metabolism. In the context of this, the activated vitamin B9 functions as a specific coenzyme. Consequently, the process of new cell formation is dependent on folic acid. Thus, in the case of a deficiency of this vitamin, the haematopoietic system in particular will suffer, since a relatively high cell division rate is found there. These central and important functions once again underline the importance of a sufficient daily supply of folic acid.
A deficiency can lead to a variety of symptoms
As already mentioned, tissues with a high cell division rate are particularly sensitive to a folic acid deficiency. Since blood cell formation is a prime example of a high cell division rate, it is not uncommon for a deficiency to lead to so-called megaloblastic anaemia. Precursor cells of the erythrocytes and the erythrocytes themselves are enlarged on microscopic examination as a result. There is a risk of reduced performance, fatigue and headaches, among other things. Other consequences of a deficiency can be leukocytopenia and thrombocytopenia (lack of leukocytes = defence cells and thrombocytes = important components for blood clotting), mucous membrane changes in the mouth and gastrointestinal tract, and diarrhoea.
Text sources:
(1) Biesalski et al, Pocket Atlas of Nutrition, 7th edition, 2017.
(2) Herdegen, Pharmacology and Toxicology, 4th edition, 2019
(3) Horn, Biochemistry of Humans, 7th edition, 2018.
(4) https://www.dge.de/wissenschaft/referenzwerte/folat/
(5) Khan and Jialal, Folic Acid (Folate) Deficiency, 2020.
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