Commentary on Understanding Elevated Vitamin D Measurements to Uncover Hypercalcemia Etiology

probable cross-reactivity with 1,24,25(OH) 3 D (this information is not displayed in the manufacturer's instructions for use).This report confirms the superiority of LC-MS/MS over immunoassays for the measurement of vitamin D metabolites and emphasizes the role of 1,24,25(OH) 3 D in vitamin D intoxication.Indeed, this metabolite can also actively bind the vitamin D receptor with approximately 50% of the affinity of 1,25(OH) 2 D and can cause hypercalcemia (1).Finally, this report raises concerns about the reliability of "unregulated" vitamin D supplements, which potentially do not contain the claimed vitamin D content, advocating for the use of pharmaceutical-grade vitamin D supplements (2).