PTH and chronic kidney disease: In terms of real-world data, for example, a prospective study by Isakova et al. (2020) [4] reports the dynamics of vitamin D, PTH, and mineral markers for 847 CKD patients progressing to ESRD over a span of 8 years; as mean eGFR declined from 32.2 to 10.1 mL/min/1.73 m2, median PTH-levels steadily increased to more than twice the baseline value, from 74.1 to 156.5 pg/mL.