Vitamin B12 (Cobalamin):
Neurological symptoms of B12 deficiency may include: numbness and tingling of the arms and legs; problems walking; disorientation; memory loss; mood changes that may resemble schizophrenia; and dementia. Damage may occur to the myelin sheath which surrounds and insulates nerves like the plastic coating around an extension cord. Nerve damage and mental health symptoms may become permanent with long term deficiency of vitamin B12.
Digestive symptoms may include: loss of appetite, a painful tongue, and constipation. The reason for there to be digestive symptoms associated with B12 deficiency is not well understood. One theory suggests that undiagnosed digestive problems might have been an initial cause of the B12 deficiency.
Symptoms of vitamin B12 deficiency may include pernicious anemia and megaloblastic anemia which are hemoglobin deficiencies that have symptoms of tiredness. Folate deficiency symptoms are also possible because B12 is necessary in folate metabolism. Increased heart disease risk from elevated homocysteine levels may result from B6, B12, or folate deficiency.
Malabsorption problems, chronic use of antacids and being over age 60 may increase the risk of B12 deficiency. A cofactor and normal stomach acidity levels are necessary for B12 absorption. Some individuals receive monthly injections of B12. Sublingual tablets are absorbed in the mouth.
Food Sources of Vitamin B12 include: shellfish, fish, meat, poultry, eggs, milk, cheese, dairy products, Nutritional or Brewer’s yeast. Vegetarians who don’t eat dairy, eggs, fish or other meat products may need a supplement or nutritional yeast, a vegan food source of vitamin B12.
Injections of B12 may be needed for better absorption of the nutrient for some individuals with stomach problems. Adequate stomach acid and a cofactor are required for normal absorption of vitamin B12. A genetic difference may exist that causes some individuals to require the methylated active form of B12 rather than being able to benefit from the more commonly available unmethylated supplement. [More about methylcobalamin.]
Reference for more information:
An Evidence-based Approach to Vitamins and Minerals: Health Benefits and Intake Recommendations, 2nd Ed., by J. Higdon & V. Drake, (Thieme, Stuttgart / New York, 2012)
/Disclaimer: This information is provided for educational purposes within the guidelines of fair use. While I am a Registered Dietitian this information is not intended to provide individual health guidance. Please see a health professional for individual health care purposes./Vitamin B12 deficiency can cause long term nerve degeneration by Jenny