Among the many vitamins and minerals that our body needs, vitamin B12 or cobalamin plays an essential role for our body. It belongs to the group B vitamins.
In this article, we will define cobalamin, analyse its benefits, recommended nutritional intakes and the consequences of deficiency or excessive consumption. We will also look at foods rich in vitamin B12 and try to understand why it is the most deficient vitamin in vegetarians.
What is vitamin B12?
Vitamin B12 or cobalamin is one of the eight B vitamins, the other seven being B1, B2, B3, B5, B6, B8 and B9.
It is essential for the proper functioning of your body and as your body does not produce it on its own, it is therefore provided by food. It is a water-soluble vitamin (like vitamin C and the other B vitamins), i. e. it is soluble in water and is excreted in the urine.
Frequent consumption is recommended to maintain your cobalamin intake, but it does not necessarily have to be daily as cobalamin can be stored in your liver to avoid a deficiency of this vitamin.
Vitamin B12 is also available as a food supplement. As we will see later in this article, these supplements are mainly used by vegans and the elderly.
The benefits of cobalamin
In order to understand why cobalamin is so important for the body, here are some of the benefits of cobalamin:
- Helps the nervous system function properly by protecting and insulating nerve fibres.
- Contributes to the protection and regeneration of your neuromediators.
- Helps in the proper functioning of cells, the formation of red blood cells and the synthesis of DNA.
- Helps in the assimilation of vitamin B6 and vitamin B9. A deficiency in vitamin B12 automatically leads to a deficiency in vitamin B9. Together, these three vitamins help reduce the risk of cardiovascular disease.
Recommended vitamin B12 intake
The recommended intake is 2. 4 μg of vitamin B12 per day for a healthy adult. This is the vitamin we need in the smallest amount, but it is not the least important for the reasons mentioned above.
The recommended dietary allowance varies from 0. 5 to 1. 3 μg/day for children, depending on their age, and up to 2. 8 μg/day for nursing mothers or 2. 6 μg of vitamin B12 per day for pregnant women.
For people engaged in strenuous physical activity, an increase in intake of 1. 5 μg/day is generally recommended. The total recommended intake for a physically active adult is therefore 2. 4 μg + 1. 5 μg = 3. 9 μg/day.
Foods rich in vitamin B12
Cobalamin is found almost exclusively in foods of animal origin.
Some of the everyday foods with the highest vitamin B12 intake are beef liver 65 μg/100 grams, calf liver 60 μg/100 grams, oysters 14. 5 μg/100 grams, mackerel 9 μg/100 grams, herring 8. 5 μg/100 grams, mussels 8 μg/100 grams and beef 5 μg/100 grams of lean meat.
There is some vitamin B12 in plant foods (some seaweed and fermented products such as sauerkraut, beer, kimchi or tamari sauce) but the absorption of the vitamin in these foods is not well absorbed by the body.
Vegetarians, who tend to be deficient in cobalamin, will be able to cover their daily intake by consuming eggs (1. 8μg/100 grams) and dairy products such as camembert or emmental 3μg/100 grams, cottage cheese 0. 9 μg/100 grams or cow's milk 0. 4 μg/100 grams.
For vegans, who do not consume any animal products, there are no natural sources of cobalamin. This is the main limitation of this diet, which also has a number of benefits for your body.
Vitamin B12 supplements or fortified foods, such as some soy-based vegetable preparations, can help avoid cobalamin deficiency for vegans. These supplements should be added when eating other foods to facilitate their absorption.
Note that cobalamin is sensitive to light and heat, so cooking foods can reduce their cobalamin intake. Avoid high-temperature cooking: two minutes of high-temperature cooking can reduce the amount of cobalamin by 30%.
The consequences of deficiency or excessive consumption
We have a high stock of vitamin B12 in the body, so it is sometimes difficult to detect a vitamin B12 deficiency unless it has been present for several years.
The people most at risk of vitamin B12 deficiency are:
- The elderly. Cobalamin is always combined with protein before being separated in the stomach. Many elderly people, however, have too low a stomach acidity for this separation to take place and so there is a risk that the cobalamin will not be absorbed by the body.
- People who regularly consume alcohol or tobacco. A large amount of vitamin B12 is used to help eliminate alcohol and drugs from our bodies. These substances also attack our liver, making it more difficult to absorb vitamin B12.
- Vegetarians and vegans, for the reasons we have seen.
- Prolonged cobalamin deficiency can lead to serious consequences such as neurological disorders, memory loss, fatigue, mood disorders and even some types of dementia.
Excessive consumption of cobalamin
Cobalamin is a water-soluble vitamin, any excess of this vitamin will be eliminated via the kidneys through the urine. There is therefore no major risk of excess vitamin B12, but excessive consumption over a long period of time can put a strain on the kidneys.
Conclusion
As you can see, cobalamin is an essential vitamin for our body. It is involved in the synthesis of DNA, the proper functioning of the nervous system, the formation of red blood cells and the absorption of vitamin B6 and vitamin B9.
It is provided by food, particularly through animal products such as offal, red meat, poultry, shellfish (such as oysters, mussels and clams), fish, dairy products (mainly cheese) and eggs.
