- List of foods rich in vitamin B12
- Forms of vitamin B12 and intestinal absorption
- People at risk of disability
- Vitamin B12 and Vegetarians
- Recommended amount of vitamin B12
- Too much vitamin B12
Foods rich in vitamin B12 are especially those of animal origin, such as fish, meat, eggs and dairy products, and it performs functions such as maintaining the metabolism of the nervous system, the formation of DNA and the production of healthy red blood cells for the blood, preventing anemia.
Vitamin B12 is not present in foods of plant origin, unless they are fortified with it, that is, the industry artificially adds B12 in products such as soy, soy meat and breakfast cereals. Therefore, people with a vegan diet should be aware of the consumption of B12 through fortified foods or through the use of supplements.
List of foods rich in vitamin B12
The following table shows the amount of vitamin B12 in 100 g of each food:
| Foods | vitamin B12 in 100 g of food |
| Cooked liver steak | 72.3 mcg |
| Steamed seafood | 99 mcg |
| Cooked oysters | 26.2 mcg |
| Cooked chicken liver | 19 mcg |
| Baked heart | 14 mcg |
| Cooked herring | 10 mcg |
| Cooked crab | 9 mcg |
| Cooked salmon | 2.8 mcg |
| Grilled trout | 2.2 mcg |
| Mozzarella cheese | 1.6 mcg |
| milk | 1 mcg |
| Cooked chicken | 0.4 mcg |
| Cooked meat | 2.5 mcg |
| Tuna fish | 11.7 mcg |
Vitamin B12 is present in nature in very small amounts, which is why it is measured in micrograms, which is 1000 times less than the milligram. Its recommended consumption for healthy adults is 2.4 mcg per day.
Vitamin B12 is absorbed in the intestine and stored mainly in the liver. Therefore, the liver can be considered one of the main dietary sources of vitamin B12.
Forms of vitamin B12 and intestinal absorption
Vitamin B12 exists in several forms and is usually linked to the cobalt mineral. This set of forms of B12 is called cobalamin, with methylcobalamin and 5-deoxyadenosylcobalamin being the forms of vitamin B12 active in human metabolism.
In order to be well absorbed by the intestine, vitamin B12 needs to be disconnected from proteins through the action of gastric juice in the stomach. After this process, it is absorbed at the end of the ileum together with the intrinsic factor, a substance produced by the stomach.
People at risk of disability
It is estimated that about 10 to 30% of the elderly are unable to absorb vitamin B12 properly, being necessary to use supplements in capsules of this vitamin to prevent problems such as anemia and nervous system malfunction.
In addition, people who have undergone bariatric surgery or who use drugs that reduce stomach acid, such as Omeprazole and Pantoprazole, also have impaired vitamin B12 absorption.
Vitamin B12 and Vegetarians
People with a vegetarian diet find it difficult to consume adequate amounts of vitamin B12. However, vegetarians who include eggs and dairy products in their diet tend to maintain good levels of B12 in the body, with no need for supplementation.
On the other hand, vegans usually need to take B12 supplements, in addition to increasing the consumption of cereals such as soy and derivatives fortified with this vitamin. Food fortified with B12 will have this indication on the label, showing the amount of vitamin in the nutritional information of the product.
It is important to remember that the blood test is not always a good B12 meter, as it may be normal in the blood, but deficient in the cells of the body. In addition, as vitamin B12 is stored in the liver, it can take about 5 years for the person to start having symptoms of deficiency of this vitamin or until the tests have altered results, as the body will initially consume the previously stored B12.
Recommended amount of vitamin B12
The recommended amount of vitamin B12 varies with age, as shown below:
- From 0 to 6 months of life: 0.4 mcg From 7 to 12 months: 0.5 mcg From 1 to 3 years: 0.9 mcg From 4 to 8 years: 1.2 mcg From 9 to 13 years: 1.8 mcg From 14 years onwards: 2.4 mcg
Along with other nutrients like iron and folic acid, vitamin B12 is essential to prevent anemia. See also iron-rich foods for anemia.
Too much vitamin B12
Excess vitamin B12 in the body can cause small changes in the spleen, changes in lymphocytes and increase in lymphocytes. This is not very common, as vitamin B12 is well tolerated by the body, but it can occur if the individual takes vitamin B12 supplements without medical supervision.
