Revised D-A-CH Reference Values for the Intake of Vitamin B6

Background: The Nutrition Societies of Germany, Austria, and Switzerland as the joint editors of the "D-A-CH reference values for nutrient intake" have revised the reference values for vitamin B-6 in summer 2019. Summary: For women, the average requirement (AR) for vitamin B-6 intake was derived on the basis of balance studies using a pyridoxal-5 '-phosphate (PLP) plasma concentration of >= 30 nmol/L as a biomarker of an adequate vitamin B-6 status. The recommended intake (RI) was derived considering a coefficient of variation of 10%. The RIs of vitamin B-6 for men, children, and adolescents were extrapolated from the vitamin B-6 requirement for women considering differences in body weight, an allometric exponent, growth factors as appropriate, and a coefficient of variation. For infants aged 0 to under 4 months, an estimated value was set based on the vitamin B-6 intake via breast feeding. The reference value for infants aged 4 to under 12 months was extrapolated from the estimated value for infants under 4 months of age and the average vitamin B-6 requirement for adults. The reference values for pregnant and lactating women consider the requirements for the foetus and the loss via breast milk. Key Messages: According to the combined analysis of 5 balance studies, the AR for vitamin B-6 to ensure a plasma PLP concentration of >= 30 nmol/L is 1.2 mg/day for adult females and the extrapolated AR for adult males is 1.3 mg/day. The corresponding RIs of vitamin B-6 are 1.4 mg/day for adult females and 1.6 mg/day for adult males, independent of age. For infants, the estimated value is 0.1 mg/day and 0.3 mg/day, depending on age. The AR of vitamin B-6 for children and adolescents ranges between 0.5 and 1.5 mg/day, and the RI is between 0.6 mg/day and 1.6 mg/day. During pregnancy, the AR is 1.3 mg/day in the first trimester and 1.5 mg/day in the second and third trimesters; the RI is 1.5 mg/day in the first trimester and 1.8 mg/day in the second and third trimesters. For lactating women, the AR is 1.3 mg/day and the RI is 1.6 mg/day.