Vitamin B12: what is it for and where is it found?

What is Vitamin B12?

Vitamin B12 , also known as cobalamin , is a water-soluble vitamin essential for the proper functioning of our bodies. Unlike other B vitamins, B12 contains cobalt and is the only vitamin the body can store in significant quantities, primarily in the liver.

What is Vitamin B12 used for?

Vitamin B12 performs many vital functions for our health:

1. Production of red blood cells

B12 is essential for the formation of red blood cells. A deficiency can lead to megaloblastic anemia , characterized by abnormally large red blood cells that are unable to transport oxygen efficiently.

2. Nervous system health

This vitamin is essential for the synthesis of myelin , the protective sheath that covers nerves. It maintains healthy nerve function and prevents neurological damage that can manifest as tingling, numbness, and balance problems.

3. DNA synthesis

B12 participates in the replication of DNA, the genetic material present in all cells. It is therefore crucial for cell growth and tissue regeneration.

4. Energy metabolism

It helps convert carbohydrates into glucose, the body's main source of energy. A deficiency can cause chronic fatigue and muscle weakness.

5. Cardiovascular health

B12, together with folic acid and vitamin B6, helps reduce blood levels of homocysteine , an amino acid that, if elevated, increases the risk of cardiovascular disease.

6. Cognitive function and mood

Studies show that adequate B12 levels are associated with improved cognitive performance and may help prevent age-related cognitive decline. Furthermore, the vitamin is involved in the production of neurotransmitters such as serotonin, positively influencing mood.

Where is Vitamin B12 found?

Vitamin B12 is found naturally only in foods of animal origin:

Main food sources

Meat and offal

• Beef liver (the richest source): 60-80 μg per 100g
• Beef: 2-3 μg per 100g
• Chicken meat: 0.3-0.4 μg per 100g

Fish and seafood

• Clams: 84 μg per 100g
• Mackerel: 19 μg per 100g
• Salmon: 3-4 μg per 100g
• Tuna: 2-3 μg per 100g
• Sardines: 8-9 μg per 100g

Dairy products

• Mature cheeses: 1-3 μg per 100g
• Milk: 0.4-0.5 μg per 100ml
• Yogurt: 0.4-0.6 μg per 100g

Egg

• Whole eggs: 1-2 μg per egg (mainly in the yolk)

Fortified foods

For those who follow vegetarian or vegan diets, there are foods enriched with B12:

• Fortified breakfast cereals
• Fortified plant-based drinks (soy, almond, oat)
• Enriched nutritional yeast
• Fortified soy products

Daily requirement

Vitamin B12 requirements vary according to age:

• Adults : 2.4 μg per day
• Pregnant women : 2.6 μg per day
• Breastfeeding women : 2.8 μg per day
• Children (1-3 years) : 0.9 μg per day
• Children (4-8 years) : 1.2 μg per day
• Adolescents (9-13 years) : 1.8 μg per day

Who is at risk of deficiency?

Some categories of people are more prone to vitamin B12 deficiency:

• Vegetarians and vegans : since they do not consume foods of animal origin, they require supplementation
• Elderly : With age, the ability to absorb B12 decreases.
• People with gastrointestinal disorders : celiac disease, Crohn's disease, atrophic gastritis
• Those who have had gastric surgery : Removing part of the stomach reduces absorption
• Those taking specific medications : metformin, proton pump inhibitors, antacids

Deficiency symptoms

A vitamin B12 deficiency may manifest itself with:

• Chronic fatigue and weakness
• Anemia
• Tingling and numbness in hands and feet
• Difficulty balancing
• Memory problems and confusion
• Depression and mood swings
• Glossitis (inflamed tongue)
• Respiratory difficulties

Integration

When diet is insufficient or conditions reduce absorption, supplementation is necessary. Vitamin B12 supplements are available in various forms:

• Cyanocobalamin : the most stable and common synthetic form
• Methylcobalamin : active form, more bioavailable
• Hydroxocobalamin : used in intramuscular injections

Administration methods include sublingual tablets, capsules, drops, and intramuscular injections for more severe cases.

Conclusion

Vitamin B12 is an essential nutrient for numerous vital functions in our body. Ensuring adequate intake through diet or, when necessary, supplementation is essential for maintaining good physical and mental health.

If you suspect a vitamin B12 deficiency or want to know which supplement is best for your needs, consult your doctor or pharmacist for personalized advice.