Relationship between serum levels of calcium, magnesium and phosphorus in infants with vitamin D deficiency

Background. The present study was conducted with the aim of investigating the relationship between vitamin D deficiency and the serum levels of calcium, magnesium and phosphorus. Methods. In this descriptive sectional study, infants who were admitted to the neonatal and NICU of Tehran Children's Medical Center Hospital with any diagnosis during 2018-2020 with vitamin D deficiency or insufficiency were included in the study. Serum levels of calcium, magnesium and phosphorus, and their relationship with vitamin D deficiency were recorded and investigated. Results. Among 400 included infants, 197 neonates (49.3%) had vitamin D deficiency and 203 (50.7%) had vitamin D insufficiency. The average serum level of vitamin D in studied infants was 11.477±3.55 ng/ml. There was no statistically significant relationship between the serum level of vitamin D in newborns and the serum levels of magnesium and phosphorus (P value = 0.118 and P value = 0.511), but there was a statistically significant relationship between the serum level of vitamin D and the serum level of calcium (P=0.0001). There was no statistically significant relationship between the level of serum vitamin D in newborns with the age and the gestational age of the newborn (P = 0.132 and P = 0.651). Still, a direct and significant statistical relationship was observed with the newborn's weight (P = 0.049). The average length of hospitalization in the examined infants was 16.39 ± 16.36 days. Pearson’s correlation coefficient indicated the presence of an inverse and significant correlation between the level of serum vitamin D in infants and the duration of hospitalization (P=0.036). In such a way with the reduction of vitamin D serum level, the time of hospitalization increased. Conclusion. This study showed a statistically significant relationship between low vitamin D serum levels with calcium serum levels. Practical Implications. In infants with low weight or hypocalcemia, there is a possibility of vitamin D deficiency. Vitamin D check is recommended to start treatment earlier and decrease the duration of hospitalization and other complications.