Low vitamin A status of the new-born appears to contribute to the risk of bronchopulmonary dysplasia (BPD), a chronic lung disease with focal loss of ciliated cells with keratinizing metaplasia and necrosis of the bronchial mucosa as well as increased mucous-secreting cells, and this acquires more importance in premature infants where serum retinol and RBP levels are significantly lower than in full-term neonates. Here, RBP4 is linked to bronchopulmonary dysplasia.