Anaemia and bone disease

Anaemia and bone disease commonly co-exist, particularly in chronic conditions such as haemoglobinopathies and chronic kidney disease. The effects on bone are mediated by multiple factors, including marrow expansion, iron overload, endocrine dysfunction, and disruptions in mineral metabolism. These changes compromise bone strength, increasing the risk of osteoporosis and fractures. Although therapeutic advances such as iron infusion and chelation therapy have significantly improved the management of anaemia and patient outcomes, their effects on bone health are often under-recognised with osteoporosis detection occurring after a fracture. Furthermore, with denosumab being a popular anti-resorptive choice amongst clinicians, an emerging and under-appreciated complication is the increasing number of case reports describing hypophosphataemia associated with concurrent anti-resorptive and parenteral iron. This review discusses the bi-directional relationship between anaemia and bone metabolism. By focusing on the central role of fibroblast growth factor-23 (FGF-23), as a link between anaemia, phosphate regulation, and bone metabolism, this review draws attention to under-recognised skeletal risks. Importantly, it offers practical recommendations for monitoring, bridging mechanistic insights with clinical practice where current guidelines remain limited.