Work out vitamin b12 requirement instantly with clear inputs, formula shown and shareable results.
Applies the life-stage vitamin B12 reference intakes and flags the situations where fortified foods or supplements are needed rather than diet alone.
Vitamin B12 reference intakes
2.4 microg/day for adults, 2.6 in pregnancy and 2.8 while breastfeeding; higher supplemental doses are used because passive absorption is inefficient
Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.
Only about 1% of a large oral dose is absorbed passively once the intrinsic factor route saturates at about 1.5 microg per meal.
Liver stores can cover two to five years, which is why vegan deficiency often appears only after a long delay.