29th April 2024

A 50-year-old woman presents with a 1-year history of diffuse musculoskeletal pain, particularly in her pelvic region and thighs.

A 50-year-old woman presents with a 1-year history of diffuse musculoskeletal pain, particularly in her pelvic region and thighs. She also reports generalised weakness and difficulty climbing stairs. She has a history of celiac disease and follows a strict gluten-free diet. She spends most of her time indoors due to her job and reports minimal sun exposure.

Investigations:

Serum calcium: Low

Serum phosphate: Low

25-hydroxy Vitamin D level: Significantly low

Alkaline phosphatase: Moderately elevated

X-ray of the pelvis: Pseudofractures and reduced bone density

Which is the most likely diagnosis?