ESPE Yearbook of Paediatric Endocrinology

The chapter on bone, growth plate and mineral metabolism has some themes that tend to recur year after year. Vitamin D is one such topic. Yet, every year brings new essential information on this vitamin, which has often been suggested to be a miracle cure for several disorders. Links to many outcomes exist, but solid data on actual benefits beyond prevention and treatment of rickets are scarce. This year the selected vitamin D papers suggest that once vitamin D sufficiency is attained, maybe not so much extra benefit will be gained for bone strength or fracture resistance. Hypophosphatemic rickets is another theme that has repeatedly been brought up in the chapter, as we have over the years followed the development of an FGF23 antibody for treatment of XLH. It has been a long path from identification of FGF23 as the “phosphatonin” to the first preclinical studies and small-scale clinical trials in adults with XLH. Finally, we have come to the stage when we can report on the first randomized trial of FGF23 antibody treatment in children with XLH. The results are very promising and we may have reached a phase when this new drug is coming to our clinics to complement the therapeutic arsenal for XLH. In addition to these recurring themes, the chapter reports, among others, on new biomarkers, new genes and on novel means to analyse growth plate regulators and function.