The Critical Role of Vitamin D Supplementation for Skeletal and Neurodevelopmental Outcomes in Preterm Neonates

Background/Objectives: Metabolic bone disease of prematurity (MBDP) is a multifactorial disorder resulting from disrupted transplacental mineral transfer and postnatal nutritional deficits, particularly affecting preterm neonates born before 32 weeks of gestation or weighing under 1500 g. Although substantial research has focused on skeletal outcomes, few studies have explored the association between MBDP and neonatal neurological impairment. This narrative review is the first to integrate the pathophysiological mechanisms, diagnostic methods, and preventive strategies for MBDP, while simultaneously investigating its potential impact on neurodevelopment. Methods: A narrative review of recent peer-reviewed studies, systematic reviews, and clinical trials was performed focusing on biochemical markers (alkaline phosphatase, FGF23, calcium, and phosphorus), emerging tools such as bioelectrical impedance analysis (BIA), and the effects of early nutritional interventions on both skeletal and neurodevelopmental outcomes in preterm infants (n = seven included articles). Results: Early elevations in ALP, particularly when combined with low serum phosphorus and FGF23 levels, provide sensitive markers for identifying MBDP. Furthermore, insufficient vitamin D levels during gestation and in the neonatal period have been associated with increased risks of seizures, hypotonia, and developmental delays. Studies suggest that enhanced vitamin D supplementation in preterm infants (up to 800 IU/day) may improve mineral absorption and bone formation and confer neuroprotective benefits through anti-inflammatory and antioxidant mechanisms. Conclusions: This is the first review on the neurological implications of biochemical actors of MBDP. As a result, diagnostic and therapeutic strategies, including vitamin D supplementation, can improve bone and neurodevelopmental outcomes. Future prospective studies are required to standardize diagnostic criteria and optimize therapeutic regimens for enhanced long-term benefits.