Vitamin B12 and Folate



The term vitamin B12 (or Cobalamine), indicates a group of substances containing cobalt. Folic acid and folate they are, however, also known as vitamin B9. Both are water-soluble vitamins, ie capable of dissolving in water, and belong to the B vitamins, very important for the body for their multiple functions.
In particular, these two substances are involved in the metabolism of fatty acids, amino acids (the "building blocks" that make up proteins) and nucleic acids (for example DNA) and are essential for the functionality of red blood cells and the functioning of the system. nervous.

Although folate and folic acid are often identified with the same name, it is important to make a distinction: dietary folate are compounds found in foods, while folic acid is the synthetic molecule present in vitamin supplements.

Foods rich in Vitamin B12

Vitamin B12, unlike most of the other vitamins, is present only in products of animal origin. We find it in meat (especially in red meats and to a large extent in liver and kidneys), in fish, molluscs but also in eggs, milk and its derivatives. In the vegetable kingdom it is mostly absent; it is contained in algae but in a form that cannot be assimilated by man.

Foods rich in folate

Foods naturally rich in folate are those of plant origin such as green leafy vegetables (spinach, broccoli, asparagus, lettuce), legumes (beans, peas), fruit (kiwifruit, strawberries and oranges) and dried fruit (such as almonds and walnuts). As for foods of animal origin, liver and other offal have rather high contents, as well as some cheeses and eggs, to be consumed however in the quantities recommended by the guidelines for proper nutrition.

Daily requirement

The average daily requirement of vitamin B12 for an adult, normally covered by the diet, is 2 milligrams (mg) per day. For pregnant and lactating women, this requirement increases to 2.2 - 2.4 mg per day.

The recommended intake of folate in the general population is 0.4 mg per day. For women, however, the daily nutritional requirement for folate increases during pregnancy and during breastfeeding. In particular, in women of childbearing age who plan, or do not exclude, a pregnancy and for those in pregnancy the recommended intake is 0.6 mg per day (since the fetus draws on maternal resources). 0.5 milligrams per day to replenish lost quantities with breast milk.

In the event that with the diet it is not possible to cover the required daily requirement of vitamin B12 and folate, it is necessary to resort to supplements.

Some foods, such as breakfast cereals, biscuits, rusks, fruit juices, are supplemented (fortified) with the addition of folic acid. fortification it is the process by which additional nutrients, usually minerals or vitamins, are added to foods.

However, a moderate use of these foods is recommended to avoid exceeding the maximum tolerable amount of total folate (natural folate and folic acid) established at 1 milligram per day from Scientific Committee on Food of the European Commission in 2000.

The supplement must always be recommended and prescribed by the attending physician.

Vitamin B12 or folate deficiency

Since both vitamin B12 and folate are substances that play a fundamental role in the production of red blood cells, a deficiency leads to megaloblastic anemia, a condition that causes the body to produce unusually large red blood cells that fail to function properly. The function of red blood cells is to carry oxygen from the lungs to tissues throughout the body through a substance called hemoglobin.

Anemia is the general term for a reduced production of red blood cells compared to normal or a reduced amount of hemoglobin for each red blood cell.


The absence of vitamin B12 in products of plant origin means that its deficiency is very frequent in those populations who, for social and / or cultural reasons, do not have access to products of animal origin (vegans, vegetarians, the elderly and poor countries ).

The same goes for folate: the failure to introduce foods rich in these substances determines the deficiency.

However, there can be other triggers, including:

  • pernicious autoimmune anemia, although rare it is a condition where the immune system attacks healthy stomach cells, preventing the body from absorbing vitamin B12 from the food you eat
  • malnutrition or malabsorption, can be caused by alcoholism, celiac disease, Crohn's disease and cystic fibrosis
  • use of drugs (for example anticonvulsants and antacids) which can affect the absorption of vitamins

Deficiencies are more common in older people, affecting approximately 1 in 10 people over the age of 75 and 1 in 20 between the ages of 65 and 74.

Many cases of vitamin deficiencies can be easily eliminated by improving your daily diet and introducing foods rich in vitamin B12 and folate.

Warnings in pregnancy

Folic acid deficiency in the early stages of pregnancy increases the risk of fetal malformations, intrauterine growth retardation and premature birth. Taking folic acid before conception reduces the risk of the fetus developing a defect by up to 70% neural tube. The neural tube is a structure of the embryo from which the central nervous system (brain, skull, spine, etc.) develops. When this structure does not close properly and completely during the first weeks of pregnancy, the unborn child develops severe malformations, which will be present at birth (congenital), known as neural tube defects (Dtn). They include: spina bifida (defect in the formation of the spinal column), anencephaly (absence of a large part of the brain and skull) and encephalocele (alteration due to a defect in the closure of the skull bones).

Folic acid deficiencies can also increase the risk of other malformations, in particular: certain cardiovascular defects present at birth, malformations of the lips and palate (cleft lip and palate), urinary tract and limb formation defects.

Often, the woman in the first month of gestation does not know that she is in this state and unfortunately, when she has the suspicion or confirmation of an ongoing pregnancy, many embryonic structures, including the neural tube, have concluded their development.

Therefore, for effective prevention it is essential that the woman begins to take 0.4 milligrams (mg) per day of folic acid from the moment she is planning to become pregnant.

According to Official recommendation for the prevention of birth defects it is necessary to start taking folic acid at least 1 month before conception and for the entire period in which pregnancy is sought up to the 3rd month of gestation.

Women at higher risk (with previous pregnancies in which neural tube defects or repeated miscarriages have occurred, or with diabetes, celiac disease or other malabsorptive diseases or who are taking antiepileptic drugs or folic acid antagonists), may needing larger quantities than recommended.


Council for Agricultural Research and Analysis of the Agricultural Economy (CREA). Guidelines for healthy eating

Italian Society of Human Nutrition (SINU). VITAMINS - Average requirement (AR), 2014

In-depth link

EpiCentro (ISS). Folic acid and folate

Ministry of Health. Folic acid and pregnancy ... sooner is better!

Grenade O, Carbone P, Mantovani A, Taruscio D (Ed.). Primary prevention of congenital malformations: activities of the Italian Folic Acid Promotion Network. Rome: Higher Institute of Health; 2013. (ISTISAN reports 13/28).

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