Background: Vitamin D deficiency is a global health problem in children. The vitamin D status of children and adolescents has not been evaluated in Bahrain. Aims: This cross-sectional study aimed to determine the prevalence of vitamin D deficiency in healthy children in Bahrain and to investigate the relationship between vitamin D level and age and sex. Methods: Medical records of children aged 1 month to 16 years who attended a vitamin D screening campaign at Al Kindi Specialized Hospital, Bahrain between September and October 2016 were reviewed. Data on sex and age were recorded and vitamin D level was measured as serum 25-hydroxyvitamin D [25(OH)D]. Children were grouped as: vitamin D sufficient [25(OH)D ≥ 75 nmol/L], vitamin D insufficient (51-74 nmol/L) and vitamin D deficient (≤ 50 nmol/L). Results: A total of 531 children were included in the study, 50.8% of whom were boys. Most of the children (93.4%) had low vitamin D levels; 78.3% were vitamin D deficient and 15.1% vitamin D insufficient. Only 6.6% were vitamin D sufficient. A significantly greater proportion of girls were vitamin D deficient than boys (P < 0.001). More primary-school children and adolescents were vitamin D deficient than preschool children (P < 0.001). A negative correlation was found between vitamin D level and age (r =-0.467; P < 0.001). Regression analysis showed that vitamin D level decreased by-2.164 nmol/L for each year of age. Conclusion: Vitamin D deficiency is a problem among healthy children in Bahrain. Public health policies or interventions are suggested to improve vitamin D status in Bahrain, especially for school-aged children.