title: Seasonal variation in serum levels of vitamin D metabolites and parathormone in geriatric patients with fractures in Southern Israel.
abstract: In 41 geriatric patients with long bone fractures, a seasonal variation was observed in the serum levels of 25-hydroxyvitamin D (25-OH-D), 1,25-dihydroxyvitamin D [1,25(OH)2D], 24,25-dihydroxyvitamin D [24,25(OH)2D] and parathormone (PTH). The serum concentrations of vitamin D metabolites correlate positively, while that of PTH correlates negatively with day length and global solar radiation in southern Israel. Our data suggest that the higher serum levels of vitamin D metabolites during the summer suppress PTH secretion. During the winter, the reduction of serum levels of vitamin D metabolites due to decreased endogenous production was accompanied by an increase in serum PTH levels.
mesh_terms: D015650:24,25-Dihydroxyvitamin D 3; D000368:Aged; D002112:Calcifediol / Q000097:blood; D002117:Calcitriol / Q000097:blood; D004100:Dihydroxycholecalciferols / Q000097:blood; D005260:Female; D050723:Fractures, Bone / Q000378:metabolism*; D006801:Humans; D007557:Israel; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood*; D012621:Seasons; D013472:Sunlight; D013997:Time Factors; D014807:Vitamin D / Q000378:metabolism*
chemical_list: D004100:Dihydroxycholecalciferols; D010281:Parathyroid Hormone; D014807:Vitamin D; D015650:24,25-Dihydroxyvitamin D 3; D002117:Calcitriol; D002112:Calcifediol