BACKGROUND: When exposed to ambient light, parenteral nutrition (PN) contamination with peroxides almost doubles, which increases oxidative stress in preterm infants, contributing to the development of bronchopulmonary dysplasia. The American Society for Parenteral and Enteral Nutrition (ASPEN) recommends complete PN photoprotection to reduce peroxide contamination and optimize its integrity but acknowledges the challenges of its implementation. In this study, a novel photoprotection procedure was tested for its effectiveness in reducing peroxide load and limiting ascorbic acid degradation, and for its feasibility and effectiveness in reducing urinary peroxide levels in preterm infants. METHODS: In vitro evaluation included neonatal lipid injectable emulsion-free PN admixtures prepared and infused according to current practice or the suggested photoprotection procedure through separation and complete shielding of intravenous multivitamin preparation from compounding to administration through photoprotected infusion sets. In vivo evaluation included a single-center randomized controlled pilot study of extremely preterm infants receiving PN according to current practice or the suggested photoprotection procedure. RESULTS: In vitro, photoprotection allowed a 44% decrease in peroxide generation (P <
0.002) and reduced by half ascorbic acid degradation in PN admixtures (P <
0.002). In vivo, 28 infants completed the study. Baseline urinary peroxide levels were similar in both groups before PN initiation, and the suggested photoprotection procedure resulted in a significant decrease in urinary peroxide levels over the first week of life (P <
0.05). CONCLUSION: The suggested procedure appears feasible and effective in reducing peroxide contamination and optimizing PN integrity, representing a step toward integrating complete photoprotection of PN as the standard of care in preterm infants.