Neighborhood Socioeconomic Status, Bone and Vitamin D Nutritional Status markers in the Chronic Kidney Disease in Children Cohort

Abstract Background Chronic Kidney Disease-Mineral Bone Disorder (CKD-MBD) contributes to significant morbidity in children with CKD, including poor growth and increased cardiovascular risk. Prior research demonstrates the role of socioeconomic status (SES) in the levels of CKD-MBD markers within a pediatric dialysis population. Little is known of the pediatric pre-dialysis CKD population. Objective To investigate the impact of neighborhood-level SES on CKD-MBD markers and vitamin D measuring children with pre-dialysis CKD. Methods A retrospective analysis of 576 participants from the Chronic Kidney Disease in Children (CKiD) study was conducted. Bone markers (calcium, phosphate, phosphate z-score, PTH, FGF23) and vitamin D nutritional status by 25-hydroxyvitamin D levels were assessed. SES was measured using Area Deprivation Index (ADI) and Median Household Income (MHI), and associations were examined using linear mixed models adjusted for demographic and clinical covariates. Results Participants residing in high deprivation areas had lower 25-OHD levels and higher rates of vitamin D deficiency. Both lower MHI and higher ADI (greater deprivation) were independently associated with lower 25-OHD, with stronger effects in Black participants. Unexpectedly, higher ADI was associated with lower intact FGF23 levels, though this relationship was attenuated upon p value correction. Conclusions Neighborhood-level SES is associated with vitamin D nutritional status and with the bone marker, intact FGF23. These findings highlight the importance of considering the socioeconomic and environmental context in vitamin D deficiency. Further research is needed to clarify mediators such as sunlight exposure, food access, medication access, and other contextual variables influencing bone health in CKD.