The Impact of Vitamin D Supplementation Duration on Early Childhood Developmental Milestones: A Retrospective Study

Background: Vitamin D plays a pivotal role in early childhood development, influencing skeletal strength, neuromuscular coordination, and neurodevelopment. This study aimed to evaluate the impact of different durations of Vitamin D supplementation on achieving developmental milestones. Methods: A retrospective study was conducted on 209 children, divided into two cohorts based on Vitamin D supplementation duration: six months (n = 102) and twelve months (n = 107). Developmental milestones were assessed across motor (sitting, walking), fine motor (object tracking, grasping), and social (smiling, speech) domains. Statistical analyses, including t-tests and effect size calculations, were performed to compare the mean ages of milestone achievement. Results: The 12-month group achieved several milestones significantly earlier than the 6-month group. These included walking, object tracking, and combining words into phrases. Differences in other milestones, such as sitting and smiling, were not statistically significant. Effect sizes ranged from small to moderate. Conclusion: Extended Vitamin D supplementation is associated with modest yet significant advancements in key developmental milestones. However, socio-environmental factors, including parental involvement, likely contributed to these differences. This study’s retrospective design limits causal interpretation, emphasizing the need for prospective, randomized studies to validate findings. These results support the potential benefits of extending Vitamin D supplementation beyond six months to optimize developmental outcomes in infants.