Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome characterized biochemically by hypophosphatemia, excessive urinary phosphate excretion, low 1,25-dihydroxyvitamin D levels, and clinically by osteomalacia, pseudofractures, bone pain, fatigue, and muscle weakness. TIO can occur in patients with a variety of benign mesenchimal tumors (hemangiopericitomas, fibromas, angiosarcomas,...

Mutations in PHEX (phosphate-regulating gene with homologies to endopeptidases on the X chromosome) and DMP1 (dentin matrix protein 1) result in X-linked hypophosphatemic rickets (HYP) and autosomal-recessive hypophosphatemic-rickets (ARHR), respectively. Specific binding of PHEX to matrix extracellular phosphoglycoprotein (MEPE) regulates the release of small protease-resistant MEPE peptides [...

Plasma 1,25-dihydroxyvitamin D levels are elevated in early pregnancy and continue to increase throughout pregnancy. They remain elevated postpartum in lactating women. The elevated levels probably represent a physiological response to increased calcium requirements.

There is wide difference of opinion as to the prevalence of rickets amolng the urban child population of Great Britain. This is, in part, attributable to the divergent standards of diagnosis accepted by various clinicians; on the one hand rickets is frequently diagnosedl because the child has sweating of the head or flabby muscles or is backward without any evidence of pathological change in th...