The primary objective of the study is to analyze the effects of vitamin D3 administration on serum levels of hepcidin and ferritin in children diagnosed with CKD. The research aims to measure these serum levels before and after vitamin D3 supplementation across different stages of kidney function, categorized by glomerular filtration rate (GFR). Specifically, it seeks to determine whether vitamin D3 can effectively reduce hepcidin levels and improve iron status as indicated by ferritin levels. The study employs a structured methodology involving children with CKD, divided into two groups based on their GFR: those with GFR \< 90 mL/min/1.73 m² and those with GFR ≥ 90 mL/min/1.73 m². Serum levels of vitamin D, hepcidin, and ferritin will be measured at baseline (before supplementation) and after a defined period of vitamin D3 administration. The research will utilize statistical analyses to compare these values within and between groups to establish any significant changes attributable to the supplementation.
