Vitamin B12, also known as cobalamin, is a water-soluble vitamin essential for several critical functions in the body, including:

1. Red Blood Cell Formation: Vitamin B12 is vital for producing red blood cells. Deficiency can lead to anemia¹.
2. Nervous System Maintenance: It plays a key role in maintaining the health of nerve cells and helps in the production of myelin, the protective sheath around nerves².
3. DNA Synthesis: B12 is required for DNA synthesis and repair, making it essential for cell formation and function³.
4. Metabolism: It aids in the metabolism of fats and proteins and is crucial for energy production⁴.

Sources of Vitamin B12

Vitamin B12 is primarily found in animal-based foods, including:

• Meat (especially organ meats like liver)
• Fish and shellfish (such as clams)
• Poultry
• Eggs
• Milk and dairy products

It is generally not found in plant foods, but some fortified cereals and nutritional yeasts may provide B12, which can be particularly useful for vegetarians and vegans¹.

Supplementation

For individuals who cannot get adequate vitamin B12 from their diet (due to vegetarian or vegan diets, certain medical conditions, or age-related absorption issues), vitamin B12 supplements are available. These supplements come in various forms such as:

• Tablets
• Sublingual (under-the-tongue) forms
• Injections
• Nasal gels⁵

Deficiency and Health Implications

Vitamin B12 deficiency can lead to several health issues including:

• Pernicious anemia
• Neurological issues such as numbness or tingling in the hands and feet, difficulty walking, memory loss, and cognitive decline
• Fatigue and weakness¹

Deficiency is most common in people over age 50, vegetarians, vegans, and those with gastrointestinal disorders that impede B12 absorption¹.

Regular B12 monitoring and consultation with healthcare providers are recommended, especially for at-risk populations, to ensure adequate intake and prevent deficiency-related complications⁵.

Footnotes

1. MedlinePlus - Vitamin B12: MedlinePlus Medical Encyclopedia ↩ ↩² ↩³ ↩⁴

2. NHS - Vitamins and minerals - B vitamins and folic acid ↩

3. NCBI Bookshelf - Vitamin B12 - Dietary Reference Intakes ↩

4. MedlinePlus - Vitamin B12: MedlinePlus Medical Encyclopedia ↩

5. NHS - Cyanocobalamin – vitamin B12 ↩ ↩²