A similar result was observed by Arora et al. in 2018, who showed that the serum PTH had a linear negative correlation with serum calcium (p<0.01,ρ=-0.421) but a linear positive correlation with serum inorganic phosphate (p<0.0.05,ρ=0.378) in CKD Grade 5 [22]. Here, PTH is linked to chronic kidney disease.