PTH and Hypocalcemia: Calcium homeostasis is strongly regulated by parathyroid hormone and vitamin D. Factors contributing to hypocalcaemia in HIV and DM include vitamin D deficiency, hypoparathyroidism and hypomagnesaemia.9,30 Our study identified hypocalcaemia as the most common electrolyte abnormality in both PLWH/DM and HIV-uninfected patients with DM.