PTH and chronic kidney disease: Vitamin D insufficiency (VDI), defined as serum total 25-hydroxyvitamin D levels (25D) below 30 ng/mL, and secondary hyperparathyroidism (SHPT), defined as elevated parathyroid hormone (PTH) levels, are two CKD-related complications that reduce quality of life [2] and have other serious consequences; yet, their real-world treatment remains variable.