ACTA ENDOCRINOLOGICA (BUC)

Objective. We aimed to determine the risk of hypercalcemia in a geriatric population with very high dose levels of 25-hydroxy-vitamin D (25(OH)D). Patients and Method. This study was designed as a retrospective, cross-sectional two-center study for examining the elderly patients with very high 25(OH)D levels (>88ng/mL) between January 2014 and December 2019. After recruitment, subgroup analyses of the patients were performed based on their calcium and vitamin D levels. Results. A total of 81.101 elderly patients, who had been evaluated for their vitamin D levels, were screened. Of the 458 (0.6%) elderly patients with 25(OH)D>88 ng/ mL according to our criteria, 217 patients with complete data were accepted into our study. The median 25(OH)D level was 103.7ng/mL (min-max:88.2-275.9). Most of the elderly patients (86.6%) with very high 25(OH)D levels were normocalcemic. When patients with hypercalcemia were compared with normocalcemic group, no difference was observed in the levels of 25(OH)D, intact parathormone (iPTH), phosphorus, alkaline phosphatase (ALP), and their age. However, the PTH suppression rate was significantly higher in hypercalcemic group (p=0.005). Conclusion. The elderly patients with very high 25(OH)D levels would appear to be mostly normocalcemic whereas life-threatening hypercalcemia would also occur. Treatment and follow-up planning should be done according to the clinical guideline recommendations.