Comparing smokers and non-smokers (Table 1),we found that smokers on dialysis were younger and had lower levels of vitamin D.Levels of FGF-23 and Klotho were not different between smokers and non-smokers.Smoking patients in the CKD group under conservative treatment had higher serum Pthan non-smokers (Table 1). Here, FGF23 is linked to chronic kidney disease.