Abstract: Objective To investigate the correlation between 1,25-(OH)₂-D₃ levels and neonatal respiratory tract infections, and to provide a basis for the prevention and treatment of neonatal respiratory tract infections. Method 120 neonates diagnosed with acute respiratory tract infection in the neonatal intensive care unit of Department of Obstetrics, Beijing Shijitan Hospital, Capital Medical University were selected as the respiratory tract infection group, 116 healthy neonates were selected as the control group in the same term, and the serum level of 1,25-(OH)₂-D₃ in each group was measured at the same time.They were divided into four groups according to the 1,25-(OH)₂-D₃ test level, 1,25-(OH)₂-D₃ >250nmol/L excessive, 1,25-(OH)₂-D₃ 75-250nmol/L appropriate, 1,25-(OH)₂-D₃ 50-74nmol/L deficient, and 1,25-(OH)₂-D₃ <50nmol/L deficient. Study data were analyzed using the IBM SPSS Statistics 24.0 statistical software. Result The level of 1,25-(OH)₂-D₃ in the respiratory tract infection group was significantly lower than that in the healthy control group [P<0.001, (85.85±18.07)nmol/L vs (119.34±26.12)nmol/L]. The proportion of 1,25-(OH)₂-D₃ deficiency in the respiratory tract infection group was significantly higher than that in the healthy control group (P<0.001). Compared with the proportion of 1,25-(OH)₂-D₃ deficiency, the difference was not statistically significant (P>0.05); the level of 1,25-(OH)₂-D₃ in the severe respiratory tract infection group was lower than that in the mild respiratory tract infection, and the difference was statistically significant Significance (P<0.05). Conclusion The level of 1,25-(OH)₂-D₃ in neonates with respiratory tract infection is significantly lower than that in normal healthy neonates. The lack or insufficiency of 1,25-(OH)₂-D₃ may lead to respiratory tract infection in neonates, vitamin D can be appropriately supplemented to prevent respiratory tract infection in the early stage.

Key words: 1, 25-dihydroxyvitamin D₃, Neonate, Respiratory tract infection