Introduction: Hypercalcemia has been described in patients with many granulomatous diseases. Elevated serum calcium levels in the setting of granulomatous disease are caused by unregulated production of 1,25-dihydroxyvitamin D by activated macrophages. More commonly, Crohn’s disease is associated with hypocalcemia caused by vitamin D deficiency resulting from ileal resection and malabsorption of fat-soluble vitamins. Here we present a case of sever hypercalcemia in a patient with Crohn’s disease secondary to elevated 1,25-Dihydroxyvitamin D. Case: 73 years old lady known to have Crohn’s disease for the last 20 years presented to hospital with abdominal pain, nausea, vomiting and altered level of consciousness. On admission her total serum Calcium was 14.3 mg/dl, ionized calcium 6.9mg/dl, serum phosphorous 5.2mg/dl, serum creatinine 3.06mg/dl with baseline of 1.1mg/dl, BUN 69mg/dl, serum albumin 3.9 g/dl, Alkaline phosphatase 84 U/L. She received IV fluids and furosemide initially. Her CT abdomen showed descending colon thickening. Colonoscopy showed hyperemic and friable mucosa at the left descending colon near the splenic flexure. Biopsy showed transmural chronic inflammation with granulomas. She was started on IV methylprednisolone. Rest of the work up for hypercalcemia showed Vit D,1,25 DiOH level of 72pg/ml, 25-Hydroxyvitamin D level of 31ng/ml, intact PTH 11pg/ml, PTH related peptid2 1.2 pmol/L and urine calcium of 420 mg/dl. She responded well to treatment and her calcium level normalized on day 4 after admission. She completed 5 days of IV steroids and was started on mesalamine and budesonide for Crohn’s disease. Concusion: This is the sixth reported case of hypercalcemia in a patient with active Crohn’s disease due to elevated 1,25-Dihydroxyvitamin D. When evaluating a patient with hypercalcemia, unregulated 1,25-dihydroxyvitamin D production by macrophages in the setting of active Crohn’s disease should be considered as a potential cause.
