Hypercalcemia in critically ill patients taking 10,000 IU of vitamin D (many solutions)
Hypercalcemia Without Hypervitaminosis D During Cholecalciferol Supplementation in Critically Ill Patients.
Nutr Clin Pract. 2019 Oct 11. doi: 10.1002/ncp.10407.
* IoM again fails to look at interactions - Nov 2010* has the graph: dangerous to have too much Calcium while having lots of vitamin D * 
Holmes WL1, Maish GO 3rd2, Minard G2, Croce MA2, Dickerson RN3.
1 Department of Pharmacy, Regional One Health, Memphis, Tennessee, USA.
2 Department of Surgery, University of Tennessee Health Science Center, Memphis, Tennessee, USA.
3 Dept of Clinical Pharmacy and Translational Science, U. of Tennessee Health Science Center, Memphis, TN, USA.
BACKGROUND:
Vitamin D deficiency during critical illness has been associated with worsened outcomes. Because most critically ill patients with severe traumatic injuries are vitamin D deficient, we investigated the efficacy and safety of cholecalciferol therapy for these patients.
METHODS:
Fifty-three patients (>17 years of age) admitted to the trauma intensive care unit who had a serum 25-hydroxy vitamin D (25-OH vit D) concentration <20 ng/mL were given 10,000 IU of cholecalciferol daily. Efficacy was defined as achievement of a 25-OH vit D of 30-79.9 ng/mL. Safety was evaluated by the presence of hypercalcemia (serum ionized calcium [iCa] >1.32 mmol/L) or hypervitaminosis D (25-OH vit D >79.9 nmol/L). Patients were monitored for 2 weeks during cholecalciferol therapy.
RESULTS:
Twenty-four patients (45%) achieved target 25-OH vit D. No patients experienced hypervitaminosis D. Hypercalcemia occurred in 40% (n = 21) of patients; 2 patients experienced an iCa >1.49 nmol/L. 25-OH vit D was significantly greater for those who developed hypercalcemia (37.2 + 11.2 vs 28.4 + 5.6 ng/mL, respectively, P < 0.001) by the second week of cholecalciferol. Of 24 patients who achieved target 25-OH vit D, 14 (58%) experienced hypercalcemia in contrast to 24% of patients (7 out of 29) who did not achieve target 25-OH vit D (P = 0.024).
CONCLUSIONS:
Cholecalciferol normalized serum 25-OH vit D concentrations in less than half of patients yet was associated with a substantial proportion of patients with hypercalcemia without hypervitaminosis D.