Randomized Controlled Trial of Calcitriol vs. Placebo Among Critically-ill Patients With Sepsis

Inclusion Criteria: * age ≥ 18 * Severe sepsis or septic shock * Central venous catheter (for blood drawing) Exclusion Criteria: * Serum calcium ≥ 10.0 mg/dl or phosphate ≥ 6.0 mg/dl, assessed within previous 48 hours * Current or recent therapy (within previous 7 days) with nutritional vitamin D at doses \>1,000 I.U. per day or activated vitamin D at any dose * History of solid organ or bone marrow transplant, primary parathyroid disease, metabolic bone disease, or sarcoidosis * Expected to die or leave the ICU within 48 hours * History of hypersensitivity or any allergic reaction to calcitriol * End stage renal disease * Acute Kidney Injury receiving intermittent renal replacement therapy * Enrolled in a competing study * Pregnancy