Vitamin B12 or cyanocobalamin may be a more important nutrient than most people think, especially as we age. The recommended intake is 2.4 micrograms for both men and women. It generally helps to:
- Maintain a healthy nervous system
- Produce DNA and normal red blood cell development
The consequences of a deficiency include:
- Neurological disorders (nervousness, tingling sensations, brain degeneration), cognitive problems (poor memory) that may be irreversible
- Pernicious anemia (an autoimmune disease)
- A B12 deficiency was reported in 39% of adults (in one study).
People who have pernicious anemia (PA) can’t absorb enough vitamin B12 from food. This is because they lack intrinsic (in-TRIN-sik) factor. As is the case with most autoimmune diseases, the incidence of PA increases with age. Although the body typically has sufficient vitamin B12 stores to last 3-5 years; when the stores have been depleted, the final stages of deficiency are often quite rapid, resulting in death in a period of months if left untreated.
We need stomach acid for B12 absorption that declines in age (estimated that about 30% of older people may not have enough for absorption). B12 in foods is combined with protein and must be released by the acid. People who consistently take acid-suppressing drugs (Prilosec, Prevacid, and Nexium) may be more at risk for developing a B12 deficiency and may need a daily B12 supplement. Synthetic B12 does not depend on stomach acid to be absorbed, but both natural and synthetic do require intrinsic factor for adequate absorption. The consequences of an overdose are not known. Excess vitamin B12 is rapidly excreted by the kidneys or is not absorbed into the bloodstream.
It is a concern that a deficiency of vitamin B12 may be missed in older people and may be possibly misdiagnosed as Alzheimer’s disease. Vitamin B12 levels are not routinely checked, particularly in older people. Although doctors often recommend injections to correct the deficiency, large doses, sublingual (under the tongue) tablets, or skin patches may work just as well.
A B12 deficiency is easy to prevent. It is recommended that people over 50 eat a well-rounded diet that includes meat, as well as fortified foods (cereal), or take higher doses of B12 supplements with your doctor’s permission. More testing of B12 levels should be included in a clinical setting for older people as well as those who do not eat animal products.
- The Facts on Vitamin-Deficiency Anemia (everydayhealth.com)