Vitamin B deficiency has been shown to affect bone mass in rodents and negatively impact bone formation in humans. In this study using mouse models, we define the effect of B supplementation in the wild-type mother and B deficiency in a mouse genetic model ( mice) during gestation on bone and muscle architecture and mechanical properties in the offspring. Analysis of bones from 4-wk-old offspring of the wild-type mother following vehicle or B supplementation during gestation (from to ) showed an increase in bone mass caused by an isolated increase in bone formation in the B-supplemented group compared with vehicle controls. Analysis of the effect of B deficiency in the mother in a mouse genetic model ( mice) on the long bone architecture of the offspring showed a compromised cortical and trabecular bone mass, which was completely prevented by a single injection of B in the B-deficient mothers. Biomechanical analysis of long bones of the offspring born from B-supplemented wild-type mothers showed an increase in bone strength, and conversely, offspring born from B-deficient mothers revealed a compromised bone strength, which could be rescued by a single injection of B in the B-deficient mother. Muscle structure and function analysis however revealed no significant effect on muscle mass, structure, and grip strength of B deficiency or supplementation in mice compared with littermate controls. Together, these results demonstrate the beneficial effect of maternally derived B in the regulation of bone structure and function in the offspring.