Literature data suggest that vitamin D (VD) deficiency may adversely affect many systems of the body, not only skeletal system, as believed earlier, but also central nervous cardiovascular urinary and immune which is particularly important for patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Two consecutive studies VD after HSCT in pediatric showed was associated w...

CONTEXT Improving vitamin D status may be an important modifiable risk factor to reduce falls and fractures; however, adherence to daily supplementation is typically poor. OBJECTIVE To determine whether a single annual dose of 500,000 IU of cholecalciferol administered orally to older women in autumn or winter would improve adherence and reduce the risk of falls and fracture. DESIGN, SETTIN...

It is generally recognized that glucocorticoid administration may diminish calcium absorption in vivo as well as the active transport of calcium by the intestine in vitro. Recent studies by others have emphasized the possibility of an alteration in the metabolism of vitamin D to 25-hydroxycholecalciferol in accounting for the steroid effects on calcium absorption. The results obtained in the pr...

A biologically active vitamin D(3) metabolite ("peak V metabolite") more polar than 25-hydroxycholecalciferol has been isolated from chicken intestines in pure form as a mono(trimethylsilyl)ether derivative. The molecule has been identified as 1,25-dihydroxycholecalciferol by means of mass spectrometry, ultraviolet absorption spectrophotometry, and specific chemical reactions.

BACKGROUND Female adolescent runners have an elevated prevalence of low bone mass for agemdashan outcome that may be partially due to inadequate energy intake. OBJECTIVE The objective was to evaluate diet, menstrual history, serum hormone concentrations, and bone mass in female adolescent runners with normal or abnormal bone turnover. DESIGN Thirty-nine cross-country runners (age: 15.7 plus...

(23S)-23,25-Dihydroxycholecalciferol was converted into at least five metabolites in kidney homogenates prepared from 1,25-dihydroxycholecalciferol-treated chickens. One of these has been positively identified as 23,25,26-trihydroxycholecalciferol by u.v.-absorbance analysis, mass spectrometry and chemical formation of derivatives. 23,25,26-Trihydroxycholecaciferol produces 25-hydroxycholecalci...