Relationship between fibroblast growth factor 23 level and vitamin D status in chronic kidney disease: A cross-sectional study

Complications stemming from chronic kidney disease (CKD) significantly contribute to increased morbidity and mortality rates. During the early stages of CKD, a delicate balance in homeostasis and mineral regulation is maintained largely due to fibroblast growth factor 23 (FGF-23). However, as kidney function declines, there is a detrimental effect on vitamin D synthesis. Understanding the dynamics of FGF-23 levels in relation to vitamin D status is crucial for assessing kidney function and its implications on hormonal regulation, calcium homeostasis, and cardiovascular health. Therefore, this study aimed to scrutinize and comprehend the correlation between FGF-23 levels and vitamin D status in patients afflicted with CKD. Methods. A cross-sectional study was undertaken at Dr. Wahidin Sudirohusodo Hospital in Makassar, South Sulawesi, Indonesia, involving 58 patients diagnosed with stage 3-5 non-dialysis CKD. Relationships between FGF-23 level with vitamin D level status and CKD stage were analyzed by chi-square and Kruskal-Wallis test. Results. The FGF-23 levels, with a median of 100 pg/mL as the designated cut-off, exhibit significance concerning the levels of vitamin D (p=0.003). The average values of FGF-23 in cases of deficiency and insufficiency are markedly elevated when compared to patients with sufficient vitamin D levels (p=0.016). The significance of FGF-23 levels becomes more prominent with advancing CKD stages (p=0.06). Conclusions. FGF-23 is a related marker with vitamin D deficiency in patients with CKD but is inconsistent in stage development and not an independent factor.