Rickets and Osteomalacia (Acquired and Heritable Forms)

Abstract

Rickets and osteomalacia refer to the consequences of generalized impairment of skeletal mineralization during growth and adult life, respectively. Among the complications can be deformity, fracture, weakness, and pain. The many acquired or heritable causes typically involve low circulating levels of inorganic phosphate (Pi), often with hypocalcaemia and secondary hyperparathyroidism. Commonly, the pathogenesis features deficiency of vitamin D leading to malabsorption of dietary calcium (Ca). Especially rare forms involve aberrant bioactivation or action of vitamin D, elevated circulating levels of a phosphatonin (typically fibroblast growth factor 23) that cause renal Pi wasting and hypophosphatemia, or alkaline phosphatase deficiency. All types have some medical treatment, but success depends on correcting the aetiology or effectively addressing the pathogenesis, often requiring supplementation with vitamin D or an analogue together with Ca or Pi. Although general guidelines for therapy may be available, skilled personalized treatment and follow-up are key to safe and successful outcomes.