Vitamin B12 deficiency gives rise to pernicious anemia and neurological disorders; important among many other conditions.
Certain people cannot get this vitamin from food when they suffer from;
- A type of autoimmune gastritis, where acid and intrinsic factor producing cells in stomach are destroyed.
- Removal of major portion of stomach as in stomach cancer or major portion of intestine.
- As normal acidic environment is required for its absorption, chronic acid suppressants like PPIs (Proton pump inhibitors) taken for various conditions may cause its deficiency.
- Gastric bypass surgeries conducted for certain diseases, as in obesity.
- Worms in intestine may eat up a major portion of vitamin available in food.
- Overgrowth of certain pathologic bacteria may hamper its availability.
- Diseases of mal-absorption syndromes like irritable bowel syndrome and celiac disease etc. affect absorption.
- Certain chemotherapeutic drugs and metformin an anti-diabetic may cause its deficiency.
- Those who fully depend on vegetarian diet.