Hypovitaminosis D-Induced Secondary Hyperparathyroidism With Concomitant Femoral Fracture in a Chronic Hepatitis B Patient: A Case Report.

Vitamin D deficiency and secondary hyperparathyroidism (SHPT) are preventable causes of metabolic bone disease, yet they may remain clinically silent until catastrophic skeletal events occur. Chronic hepatitis B virus (HBV) infection has been increasingly linked to disordered bone and mineral metabolism, even in the absence of cirrhosis. We report a 39-year-old man with chronic HBV infection who presented with a low-trauma subtrochanteric femoral fracture. He had no history of alcohol or tobacco use and had only recently commenced antiviral therapy. Biochemical evaluation revealed severe vitamin D deficiency, markedly elevated parathyroid hormone levels, hypophosphatemia, and raised alkaline phosphatase, consistent with SHPT and metabolic bone disease. There was no clinical or radiological evidence of liver cirrhosis. The patient underwent surgical fixation of the fracture, received vitamin D supplementation, and was initiated on Tenofovir Alafenamide, with good clinical recovery.