Scope: The nutrition societies of Germany, Austria, and Switzerland are the joint editors of the “D-A-CH reference values for nutrient intake”, which are revised regularly. Methods and Results: By reviewing vitamin-B 12 -related biomarker studies, the reference values for vitamin B 12 were revised in 2018. For adults, the estimated intake is based on the adequate serum concentrations of holotranscobalamin and methylmalonic acid. The estimated values for children and adolescents are extrapolated from the adult reference value by considering differences in body mass, an allometric exponent, and growth factors. For infants below 4 months of age, an estimated value is set based on the vitamin B 12 intake via breast milk. The reference values for pregnant and lactating women consider the requirements for the fetus and for loss via breast milk. The estimated values for vitamin B 12 intake for infants, children, and adolescents range from 0.5 to 4.0 µg d −1 . For adults, the estimated values are set at 4.0 µg d −1 , and for pregnant and lactating women, they are set at 4.5 and 5.5 µg d −1 , respectively. Conclusion: Based on the data of several vitamin B 12 status biomarkers studies, the reference value for vitamin B 12 intake for adults is raised from 3.0 to 4.0 µg d −1.