Presentation of latent tuberculosis with elevated calcitriol as the first-presenting sign: A case report

This case report sheds light on an unusual clinical presentation of elevated calcitriol levels and low cholecalciferol, serving as a potential early indicator of latent tuberculosis infection (LTBI). While hypercalcemia, along with the same vitamin D3 picture, has been notably associated with active tuberculosis (TB). What sets this case apart is mildly elevated calcium levels and high calcitriol, all occurring within the context of LTBI. This case report presents a 52-year-old male with mild hypercalcemia and elevated 1,25-dihydroxy vitamin D3 and low 25 hydroxy vitamin D3, revealing a unique biochemical profile. An insignificant chest x-ray with a positive QuantiFERON TB test ultimately confirmed LTBI. The patient was subsequently initiated on a four-month rifampin regimen for LTBI treatment. This case underscores the importance of recognizing elevated calcitriol levels as a potential early sign of latent TB infection.