Vitamin B12 is an essential nutrient that the human body cannot produce on its own. It plays a role in many biological processes, from supporting nervous system function and producing red blood cells to DNA synthesis and energy metabolism. Unlike many other vitamins, B12 can be stored in the body for long periods. However, inadequate intake or absorption problems may eventually lead to deficiency.

Sometimes B12 deficiency shows clear symptoms, while at other times it develops slowly and remains unnoticed. Whether it is detected early or late can significantly influence the severity of its effects.

What Is Vitamin B12 and What Are Its Functions?

Scientifically known as cobalamin, vitamin B12 is a water-soluble vitamin. It is actively involved in metabolic reactions responsible for cellular energy production, the protection of nerve cells, and the formation of the building blocks of genetic material.

Its main functions include:

• Nervous system health – contributes to the maintenance of the myelin sheath.
  
  
• Red blood cell production – plays a role in the maturation process of red blood cells in the bone marrow.
  
  
• DNA synthesis – essential for cell division and renewal.
  
  
• Energy metabolism – functions as a coenzyme in certain steps of protein and fat metabolism.
  
  

Vitamin B12 is found in animal-based foods. Since the human body cannot synthesize it, B12 must be obtained through diet or supplementation.

What Are the Symptoms of Vitamin B12 Deficiency?

Mild B12 deficiency may go unnoticed, but as levels drop further, a wide range of symptoms can appear across different body systems.

• Persistent fatigue and weakness
  
  
• Memory issues, forgetfulness, and difficulty concentrating
  
  
• Tingling or numbness in hands and feet
  
  
• Muscle weakness
  
  
• Pale skin
  
  
• Mood swings or low motivation
  
  
• Balance problems and dizziness
  
  
• Shortness of breath or easy fatigue
  
  
• Redness and soreness of the tongue
  
  

If left untreated for a long time, some of these symptoms may become permanent. Regular health check-ups can help detect deficiencies early.

What Causes Vitamin B12 Deficiency?

There are generally two main mechanisms behind B12 deficiency: inadequate intake or absorption problems.

• Dietary insufficiency: Vegan and vegetarian diets may lack sufficient B12 due to limited consumption of animal products.
  
  
• Stomach and intestinal issues: Low stomach acid, gastric surgeries, or conditions like celiac and Crohn’s disease can interfere with absorption.
  
  
• Pernicious anemia: An autoimmune condition where the body cannot produce the “intrinsic factor” needed for B12 absorption.
  
  
• Advancing age: Stomach acid production tends to decrease with age, making it harder to release and absorb B12 from food.
  
  
• Medication use: Long-term use of acid-reducing drugs or certain diabetes medications like metformin may lower B12 levels.
  
  

Which Foods Contain Vitamin B12?

Vitamin B12 naturally occurs only in animal-based foods. Main dietary sources include:

• Red meat and organ meats
  
  
• Fish and seafood
  
  
• Poultry such as chicken and turkey
  
  
• Eggs
  
  
• Milk and dairy products
  
  

The Role of Nutrition in Preventing Vitamin B12 Deficiency

Maintaining balanced and varied nutrition is essential for healthy B12 levels. In addition to animal-based proteins, fortified plant-based milks, breakfast cereals, and certain types of nutritional yeast can contribute to daily intake.

For individuals who consume limited amounts of animal products, tailoring their diet to include alternative B12 sources may be beneficial. A diverse diet can also help minimize the risk of deficiencies linked to eating patterns that lack variety.

Vitamin B12 deficiency is a condition that can arise from many different causes and affect various body systems. Symptoms usually develop gradually and may be confused with other health issues. Regular check-ups can play an important role in detecting deficiency early.

Source:

1. https://my.clevelandclinic.org/health/diseases/22831-vitamin-b12-deficiency
2. https://www.mayoclinic.org/drugs-supplements-vitamin-b12/art-20363663#:~:text=Vitamin%20B%2D12%20(cobalamin),meat%2C%20fish%20and%20dairy%20products.
3. https://www.health.harvard.edu/staying-healthy/the-a-list-for-vitamin-b-12-sources