To evaluate the influence of dietary taurine supplementation on vitamin D absorption, we studied three groups of infants: 21 (11 preterm) were fed a taurine‐free formula, 21 (10 preterm) were fed a taurine‐supplemented formula (50 mg/100 g of powder) and 20 (9 preterm) were fed human, not heat‐treated milk. Taurine, total bile acids, glyco‐(GBA) and tauro‐(TBA) conjugated bile acids, 25–hydroxyvita‐min D3 (250HD3) and 1,25–dihydroxyvitamin D3 (1,250H2D3) were determined in all infants at birth in blood cord and at one and three months of life. In preterm infants fed a taurine‐free formula, we found lower plasma taurine levels than in infants of other groups at one and three months of life. In these infants, GBA predominated, with a G/T ratio of 1.1 and 1.4 at one and three months of life, whereas in all other infants TBA predominated with a G/T ratio always