ESA-SRB-AOTA 2019

Secondary hyperparathyroidism and severe hypercalcaemia due to vitamin D deficiency (#591)

Jessica Disler 1 , Mark Savage 1 , Jessica Triay 1
  1. Department of Diabetes and Endocrinology, Bendigo Health, Bendigo, Victoria, Australia

Case presentation

An 18-year-old male of African and Caucasian ethnicity presented with two-years of fatigue and myalgia. Biochemistry revealed hypercalcaemia (corrected calcium 3.06mmol/L) and concomitant severe vitamin D deficiency (20nmol/L). Parathyroid hormone (PTH) level was markedly elevated (31.5pmol/L) with a high-normal alkaline phosphatase (137U/L). There was no clinical evidence of a granulomatous or lymphoproliferative disease. His prior medical history included a poorly healing wrist fracture and there was no relevant family history. Calcium:creatinine clearance ratio was reduced (0.0079) but vitamin D was low at 37nmol/L.

Cholecalciferol 25,000IU was administered with normalisation of vitamin D level (70nmol/L) but an associated rise in serum calcium (3.37mmol/L) and PTH (47.5pmol/L); after an interval, recommenced at 2000IU daily. Intravenous zoledronic acid (4mg) was administered with good effect. Imaging investigations included a parathyroid sestamibi scan, 4D computed tomography, ultrasound, magnetic resonance imaging, and whole-body fluorodeoxyglucose-positron emission tomography scan. Extensive surgical neck exploration failed to identify eutopic or ectopic parathyroid tissue. Despite persistent PTH elevation, he remained normocalcaemic. A final diagnosis of secondary hyperparathyroidism from severe vitamin D deficiency was made.

Discussion

Vitamin D deficiency in common in the young adult Australian population (31%) (1) with even higher rates in those with African ethnicity (2). Secondary hyperparathyroidism is a physiological response to maintain normocalcaemia and leads to osteomalacia (3). Whilst vitamin D deficiency is recognised to cause hypercalcaemia, this is typically mild (4) and a severity of this degree has not been previously reported. This case highlights the necessity to correct vitamin D deficiency to eliminate secondary hyperparathyroidism even in extreme cases of hypercalcaemia prior to further investigation or intervention. Replacement of vitamin D deficiency in the presence of hypercalcaemic hyperparathyroidism can be challenging but is generally considered safe and may ameliorate the severity of hypercalcaemia (5). An investigation algorithm for hyperparathyroidism will also be covered.

  1. Australian Health Survey: Biomedical Results for Nutrients, 2011-2012, Feature Article: Vitamin D. Australian Bureau of Statistics, 2014
  2. Benitez-Aguirre PZ, Wood NJ, Biesheuvel C, Moreira C, Munns CF. The natural history of vitamin D deficiency in African refugees living in Sydney. Med J Aust. 2009;190(8):426-8.
  3. Adams JS, Kantorovich V, Wu C, Javanbakht M, Hollis BW. Resolution of vitamin D insufficiency in osteopenic patients results in rapid recovery of bone mineral density. J Clin Endocrinol Metab. 1999;84(8):2729-30.
  4. Lam JK, Lam KS, Tan KC, Chow WS, Tso AW, Kung AW. A woman with hypophosphataemia and raised alkaline phosphatase. BMJ. 2010;340:b5564.
  5. Das G, Eligar V, Govindan J, Bondugulapati LN, Okosieme O, Davies S. Impact of vitamin D replacement in patients with normocalcaemic and hypercalcaemic primary hyperparathyroidism and coexisting vitamin D deficiency. Ann Clin Biochem. 2015;52(Pt 4):462-9.