[Possible role of the FGF23-Klotho axis in bone mineralization].
FGF23 was identified as a causative factor for hypophosphatemic rickets/osteomalacia. The following studies have confirmed its essential role in phosphate and vitamin D metabolism in normal physiology. Recent studies revealed that Klotho, originally identified as an aging-associated molecule, is necessary for the specific action of FGF23. Much attention is now paid to the FGF23-Klotho axis as a novel regulatory system in the mineral metabolism, whereas local action of FGF23 in bone metabolism or bone mineralization remains unresolved.