Three side-chain analogues of cholecalciferol (vitamin D3) modified at C-25, namely 25-fluorocholecalciferol, 24-dehydrocholecalciferol and 25-dehydrocholecalciferol, conceived as potential inhibitors of the cholecalciferol 25-hydroxylase have been prepared and tested in the rat. These compounds markedly diminish conversion in vivo of cholecalciferol into 25-hydroxycholecalciferol, but are not ...

BACKGROUND/PURPOSE The advice that an adequate vitamin D status can be achieved by short, casual exposure to summer sunlight is ubiquitous. This review will examine the value of this advice. METHODS The results of experimental studies on changes in serum 25-hydroxyvitamin D [25(OH)D] concentrations following ultraviolet exposure are interpreted in the context of human exposure to sunlight. ...

1 Health Technology Assessment Unit, Institute for Research in Extramural Medicine, VU University Medical Center, Amsterdam, The Netherlands 2 International Health Foundation, Utrecht, The Netherlands 3 Department of General Practice, Institute for Research in Extramural Medicine, VU University Medical Center, Amsterdam, The Netherlands 4 Institute for Research in Extramural Medicine, VU Univer...

this research was conducted to evaluate the effect of different zinc (zn) sources on performance, bloodmineral and cell counts of zandi lambs. 18 male lambs at weaning were supplemented with two differentsources of zinc, 25 ppm znso4 and 25 ppm zinc-peptide added to the basal diet as control. live bodyweight, weight gain and feed efficiency improved with zn-peptide supplementation (p

This interlaboratory study on determination of 25-hydroxyvitamin D (25-OH-D) in serum involved 15 laboratories in eight European countries. All could distinguish between normal (50 +/- 31 nmol/L, mean +/- SD) and grossly increased concentrations, but for eight laboratories the results for serum samples with low and normal 25-OH-D content overlapped. In general, values were well reproducible, bu...

We analyze the internal spatial wage and employment structures of the Czech Republic, Hungary, Poland, Slovenia and Slovakia, using regional data for 1996-2000. A new economic geography model predicts wage gradients and specialization patterns that are smoothly related to regions’ relative market access. As an alternative, we formulate a “Comecon hypothesis”, according to which wages and sector...