New findings suggest that very low birth weight (VLBW) preterm infants may significantly benefit from higher doses of vitamin D, leading to improved bone health. A recent study, detailed in Frontiers in Endocrinology, explored the efficacy and safety of increased vitamin D supplementation, indicating that a daily intake of 800 IU can enhance bone mineralization in these fragile newborns.

VLBW preterm infants frequently face vitamin D deficiency due to various factors, including limited exposure to ultraviolet B light, insufficient transfer of vitamin D from the mother during pregnancy, difficulties with adequate nutritional intake through feeding, and reduced fat reserves for storing the vitamin. This deficiency is a critical concern as vitamin D plays an indispensable role in overall growth and the development of bone mineral density (BMD) in infants. Prior research has consistently linked low BMD in preterm infants to a heightened risk of skeletal issues, such as osteopenia of prematurity and rickets. Vitamin D facilitates the absorption of essential minerals like calcium and phosphate, crucial for bone formation, by regulating specific transporters in the intestines. It also influences bone remodeling by interacting with vitamin D receptors in bone-forming cells and promoting the expression of key proteins involved in bone mineralization.

To assess the impact of varying vitamin D dosages, a retrospective cohort study was conducted involving 215 VLBW infants who required care at Hanyang University Seoul Hospital between 2011 and 2022. The infants, all weighing less than 1500 grams at birth, were divided into two groups: one receiving 400 IU/day and the other 800 IU/day of liquid cholecalciferol, administered orally from day 14 of life until 36 weeks postmenstrual age. The higher dosage group demonstrated significantly better whole-body bone mineral apparent density (BMAD) as measured by dual-energy X-ray absorptiometry (DEXA), with notable gains in the spine and left femur. Importantly, the study found no clinical signs of toxicity in the 800 IU/day group, suggesting that this higher regimen is safe for VLBW infants and aligns with some international guidelines that recommend higher vitamin D intake for optimal bone development.

This research underscores the considerable benefits of increased vitamin D supplementation for fortifying the skeletal structure of extremely vulnerable infants. The results advocate for a review of current standard dosing to potentially adopt higher, yet safe, levels of vitamin D to ensure these infants have a stronger foundation for life. Looking ahead, future studies should aim to validate these findings across diverse global populations and establish standardized reference values for DEXA interpretation in preterm infants, thus refining diagnostic and treatment protocols for early life bone health.