Vitamin B12: what is it for, what foods does it contain?

Vitamin B12: what is it for, what foods does it contain?

Let’s talk to experts about what supplements there are with this vitamin and what you shouldn’t combine B12 with.

  • What is this
  • Where is it kept?
  • Benefit
  • Deficiency Symptoms
  • Surplus
  • Expert commentary

The material was commented on:

Yana Denisova, gastroenterologist at the BestDoctor medical services ecosystem;

Elena Kasimtseva, family doctor at GMS Clinic.

What is vitamin B12

Vitamin B12 is a whole group of biologically active substances that are collectively called “cobalamins”. Research often refers to “cyanocobalamin,” since it is in this form that people receive the bulk of the beneficial substance, but these are not synonymous.

Vitamin B12 is needed for the normal process of cell division (hematopoiesis) and DNA formation, it prevents the development of anemia, is indispensable for the functioning of the nervous system, and stimulates concentration and memorization of information.

The vitamin was discovered in 1934, but it took the efforts of about 100 scientists from 20 countries to finally complete the chemical synthesis of cyanocobalamin 40 years later (1), (2).

Daily intake of vitamin B12:

  • up to 6 months – 0.4 mcg;
  • up to one year – 0.5 mcg;
  • up to 3 years – 0.9 mcg;
  • up to 8 years – 1.2 mcg;
  • up to 13 years – 1.8 mcg;
  • over 14 years old – 2.4 mcg;
  • pregnant and lactating women – 2.6-2.8 mcg.

What foods contain vitamin B12

Per 100 g of product (3):

  • beef liver (60 mcg);
  • goose liver (54 mcg);
  • octopus (36 mcg);
  • beef kidneys (25 mcg);
  • herring (14 mcg);
  • mussels (12 mcg);
  • chicken egg yolk (5 mcg);
  • beef meat (3 mcg).

Vitamin B12 is found in egg yolks

What is B12 used for: benefits

Vitamin B12 performs a cofactor function for two important enzymes. This means it helps fight the amino acid homocysteine ​​and reduces the risk of cardiovascular disease (4), (5), (6). In addition, the vitamin helps fight toxic methylmalonic acid and is essential for nervous system health (7).

Prevents anemia

With anemia (anemia), the content of red blood cells in the blood decreases, oxygen transport is disrupted, and hypoxia develops. It has been proven that when there is a lack of vitamin B12 in the body, red blood cells are produced in smaller quantities, become larger, and their movement in the bloodstream is more difficult. As a result, the person develops megaloblastic anemia (8).

Makes bones stronger

Scientists link vitamin B12 deficiency to high levels of homocysteine, an amino acid that increases the risk of osteoporosis, especially in women (9), (10), (11). With this disease, bones become less strong and fractures occur more often.

Prevents fetal malformations

According to scientists, a lack of B12 in the first trimester of pregnancy can trigger premature birth.
According to scientists, a lack of B12 in the first trimester of pregnancy can trigger premature birth.

According to scientists, a lack of B12 in the first trimester of pregnancy can trigger premature birth. Deficiency of this vitamin is also associated with an increased risk of fetal malformations (12), (13).

Helps eyes stay healthy

Vision also suffers from a lack of B12. A study of women over the age of 40 confirmed that getting enough of this vitamin in the diet can reduce the risk of age-related macular degeneration, which leads to loss of central vision (14), (15), (16).

Fights depression

The effects of vitamin B12 on mood are not yet fully understood. However, it has been shown to play an important role in the production of serotonin, which is responsible for our emotional well-being (17). According to doctors, taking antidepressants and a vitamin is more likely to improve the condition of patients with depression than taking medication alone (18).

Supports healthy hair and nails

Low B12 levels can lead to various dermatological problems. For example, hyperpigmentation, pale and brittle nails, inflammation of the corners of the lips (19), (20). In this case, you will need to make up for the deficit. However, if there is enough vitamin in the body, you should not take supplements with it, since they will not affect the condition of the hair or the strength of the nails (21).

Vitamin B12 deficiency

Risk factors that can provoke a lack of vitamin B12 in the body include diseases of the gastrointestinal tract
Risk factors that can provoke a lack of vitamin B12 in the body include diseases of the gastrointestinal tract

Risk factors that can cause a lack of vitamin B12 in the body include:

  • plant-based diet;
  • alcohol consumption;
  • smoking;
  • prolonged stress;
  • severe lack of calcium and iron;
  • stomach upsets;
  • elderly age;
  • diseases of the gastrointestinal tract.

Vitamin B12 deficiency may be indicated by pale yellow skin, fatigue, pain in the tongue (changes in its texture and color – glossitis), blurred vision, mood swings and nervousness, poor appetite, and memory problems.

You should contact a specialist if you are concerned about the symptoms described above or during a medical examination or preventive examination, if macrocytic anemia was detected in a general blood test.

How is hypovitaminosis B12 diagnosed and treated?

Vitamin B12: what is it for, what foods does it contain?

Surplus: What to do when B12 is elevated

Vitamin B12 supplements come in capsules, tablets, gels, or injections. Moreover, even taking high doses of B12 (1000-1500 mcg) does not cause serious consequences for the body (22).

However, in some people with individual intolerance to the vitamin, an overdose may develop pulmonary edema, urticaria, or even anaphylactic shock. You should consult your physician before taking any supplements.

Expert commentary