What are the key clinical features to consider when diagnosing osteomalacia in adults?

Key clinical features to consider when diagnosing osteomalacia in adults include:

• Diffuse bone pain, often described as aching and affecting multiple sites, particularly the lower back, hips, pelvis, and ribs.
• Muscle weakness, especially proximal muscle weakness, which may manifest as difficulty climbing stairs or rising from a chair.
• Increased risk of fractures, particularly insufficiency fractures in weight-bearing bones, which may present with localized tenderness.
• Gait disturbances or waddling gait due to bone pain and muscle weakness.
• Bone tenderness on palpation, sometimes with skeletal deformities in advanced cases.
• History of risk factors such as vitamin D deficiency, malabsorption syndromes, chronic kidney disease, or certain medications that impair bone mineralization.
• Laboratory findings supporting diagnosis include low serum calcium and phosphate, elevated alkaline phosphatase, and low or inappropriately normal vitamin D levels.

These clinical features are supported by both UK clinical guidelines and recent literature emphasizing the often subtle and nonspecific presentation of osteomalacia, which can lead to underdiagnosis Uday & Högler 2019Arboleya et al. 2023 NICE CKS[Uday & Högler 2019; Arboleya et al. 2023]. The UK guidelines highlight the importance of recognizing bone pain and muscle weakness as key symptoms in adults with suspected vitamin D deficiency-related osteomalacia NICE CKS. Recent studies also stress the need for clinical vigilance in patients with risk factors such as Fanconi’s syndrome or chronic kidney disease, where osteomalacia may present atypically Clarke et al. 1995 [Clarke et al. 1995].