PTH and chronic kidney disease: For example, in non-dialysis CKD, paricalcitol did not reduce LV mass or improve cardiac function in PRIMO and OPERA despite biochemical effects, while in hemodialysis the J-DAVID trial found no reduction in cardiovascular events with oral alfacalcidol; by contrast, extended-release calcifediol reliably raised 25(OH)D and suppressed PTH in stage 3–4 CKD, but hard outcomes remain uncertain.