What does vitamin B12 do?

Vitamin B12 is a versatile and essential vitamin. B12 is involved in, among other things, the production of substances in the nervous system, the production of red blood cells, and the production of DNA. Sufficient vitamin B12 is also necessary to keep the risk of cardiovascular diseases low, and it plays a role in the immune system. Therefore, detecting a vitamin B12 deficiency is important.

Vitamin B12 is a vitamin that must be absorbed from food because the body cannot produce B12 itself. B12 is found in dairy, meat, fish, and eggs. Vegans, due to their diet, are therefore at a higher risk of developing a vitamin B12 deficiency. However, the body stores a supply of B12 in the liver. For most people, it takes years for this supply to be depleted.

The absorption of B12 from food, its transport through the blood, and its absorption into the cell is a complex process involving many specific steps. First, the absorption of B12 from food only occurs in the last part of the small intestine, the terminal ileum. For absorption into the intestinal cell, vitamin B12 needs an auxiliary substance called 'intrinsic factor'. This substance is produced in the stomach. People who have undergone stomach or intestinal surgery are therefore at a higher risk of developing a vitamin B12 deficiency.

Vitamin B12 deficiency

A deficiency can lead to a wide range of symptoms. Sometimes years of unexplained vague complaints can ultimately be attributed to a vitamin B12 deficiency.

Because vitamin B12 is involved in many processes, it can cause many different complaints:

• Tingling feet or hands
• Numbness in the limbs
• Concentration problems
• Muscle cramps
• Fatigue
• Shortness of breath during exertion
• Dizziness
• Hair loss
• Gastrointestinal complaints

When is a vitamin B12 deficiency test recommended?

If you experience symptoms consistent with a vitamin B12 deficiency, a vitamin B12 test may be of interest. A B12 deficiency is more common with a vegan or vegetarian diet or after gastrointestinal surgery.