The relationship between maternal vitamin D levels and osteopenia development in preterm infants: A cross-sectional study

Background: Osteopenia of prematurity (OP) is characterized by reduced bone mineral content, and vitamin D deficiency may worsen OP by affecting bone metabolism.  Objective: This study aimed to investigate the correlation between maternal vitamin D levels and biochemical markers related to OP. Materials and Methods: This analytical cross-sectional study, conducted at Shahid Sadoughi hospital, Yazd, Iran, from June 2022 to September 2023, included 49 pregnant women and their preterm infants. Based on the serum alkaline phosphatase and phosphorus levels of the infants at birth and 4 wk after birth, they were divided into osteopenic and non-osteopenic groups. Maternal and neonatal vitamin D and calcium levels were then compared between these groups. Results: The mean maternal vitamin D level was 24.9 ± 15.09 ng/ml, with 36% showing deficiency. 11 neonates at 4 wk exhibited osteopenia based on phosphorus and serum alkaline phosphatase levels. Those with osteopenia had significantly lower vitamin D (p = 0.032) and calcium levels compared to non-osteopenic neonates (p = 0.043), although maternal vitamin D mean was not a significant risk factor for OP (p = 0.313).  Conclusion: The results suggest that maternal vitamin D levels do not have a significant association with the incidence of osteopenia in neonates, as the mean maternal vitamin D concentration was not identified as a risk factor for this condition. Therefore, it is recommended that future research should investigate alternative factors that may contribute to the development of osteopenia in preterm infants.