What Causes Low Vitamin B12?

Low vitamin B12 levels, also known as vitamin B12 deficiency, can be caused by various factors. Vitamin B12, also called cobalamin, is a water-soluble vitamin that plays a crucial role in the functioning of the nervous system, DNA synthesis, and the production of red blood cells. Here are some common causes of low vitamin B12 levels:

  1. Dietary Insufficiency: Vitamin B12 is primarily found in animal-based foods, such as meat, fish, poultry, eggs, and dairy products. Individuals who follow strict vegan or vegetarian diets, especially those that exclude all animal products, may be at a higher risk of developing vitamin B12 deficiency if they don’t obtain the vitamin from fortified foods or supplements.
  2. Malabsorption Disorders: Certain medical conditions can interfere with the absorption of vitamin B12 from the gastrointestinal tract. These include:
    • Pernicious Anemia: An autoimmune condition where the body attacks the cells in the stomach that produce intrinsic factor, a protein necessary for vitamin B12 absorption.
    • Atrophic Gastritis: Inflammation and thinning of the stomach lining can reduce the production of stomach acid and intrinsic factor, impairing B12 absorption.
    • Celiac Disease: An autoimmune disorder where the ingestion of gluten damages the small intestine, affecting nutrient absorption, including vitamin B12.
    • Inflammatory Bowel Disease: Conditions like Crohn’s disease or ulcerative colitis can affect the absorption of nutrients, including vitamin B12.
  3. Gastrointestinal Surgery: Certain types of gastrointestinal surgeries, such as weight loss surgery (gastric bypass) or surgeries involving the removal of parts of the stomach or small intestine, can reduce the body’s ability to absorb vitamin B12.
  4. Age: As people age, the production of stomach acid and intrinsic factor can decrease, potentially leading to reduced B12 absorption.
  5. Medications: Some medications can interfere with vitamin B12 absorption. These include proton pump inhibitors (used to reduce stomach acid), H2 blockers (used to treat acid reflux), and certain diabetes medications like metformin.
  6. Parasitic Infections: Infections with certain types of parasites, such as tapeworms, can lead to vitamin B12 deficiency.
  7. Alcohol Abuse: Excessive alcohol consumption can impair the absorption of vitamin B12 and contribute to deficiency.
  8. Genetic Factors: Some rare genetic conditions can affect vitamin B12 metabolism or absorption.

Symptoms of vitamin B12 deficiency can vary and may include fatigue, weakness, anemia, neurological symptoms (tingling, numbness, difficulty walking), memory problems, and mood changes. If you suspect you have a vitamin B12 deficiency or are experiencing these symptoms, it’s important to consult a healthcare provider for proper diagnosis and treatment. Treatment may involve dietary changes, vitamin B12 supplements, or addressing any underlying medical conditions that contribute to the deficiency.