Vitamin B12 status is typically assessed via serum or plasma vitamin B12 levels. Values below approximately – pg/mL (– picomol/L) for adults [ 5] indicate a vitamin B12 deficiency. However, evidence suggests that serum vitamin B12 concentrations might not accurately reflect intracellular concentrations [ 6 ]. Recommended Daily Allowance The Institute of Medicine's Food and Nutrition Board recommends that healthy adult men and women over 19 years old consume micrograms of vitamin B each day.
Because 10% to 30% of older people do not absorb food-bound vitamin B12 efficiently, those over 50 years should meet the RDA by eating foods fortified with B12 or by taking a vitamin B12 supplement. The Recommended Dietary Allowance (RDA) is in fact not the body’s daily requirement exactly, but rather the amount of vitamin B12 which – according to the recommendations of the corresponding organisations – should suffice to cover the minimum daily requirement of % of healthy people.
Back to Top. Food and Nutrition Board (FNB) Recommendations (#) #2: As 10 to 30 percent of older people may malabsorb food-bound B12, FNB advises those older than 50 years to meet their Recommended Daily Allowances for it by consuming foods fortified with B12 or a supplement containing B #3: In view of evidence linking folate deficiency with neural tube defects in the fetus, FNB . Bor MV, Von castel-roberts KM, Kauwell GP, et al. Daily intake of 4 to 7 microg dietary vitamin B is associated with steady concentrations of vitamin Brelated biomarkers in a healthy young population. Am J Clin Nutr. ;91(3) Darby WJ, Bridgforth EB, Le brocquy J, et al. Vitamin B12 requirement of adult .