CHANGES IN VITAMIN-D METABOLITES AND PARATHYROID-HORMONE IN PLASMA FOLLOWING CHOLECALCIFEROL ADMINISTRATION TO PREMENOPAUSAL AND POSTMENOPAUSAL WOMEN IN THE NETHERLANDS IN EARLY SPRING AND TO POSTMENOPAUSAL WOMEN IN CURACAO

To study the effect on plasma 25-hydroxycholecalciferol (25(OH)D), 1, 25-dihydroxycholecalciferol (1, 25(OH)(2)D) and parathyroid hormone (P TH) we supplemented premenopausal (aged 30 (so 7) years) and postmenop ausal (aged 61 (so 2) years) white women living in The Netherlands in late winter/early spring, and elderly black and white women (aged 75 ( so 6) years) living in Curacao (Dutch Antilles) with either 10 or 20 m u g cholecalciferol/d for 4, 5 and 9 weeks respectively, Baseline plas ma 25(OH)D concentration of Dutch women was lower than that of Curacao women, Postmenopausal Dutch women had a higher PTH concentration in p lasma than premenopausal Dutch and postmenopausal Curacao women, There were no differences in plasma 1,25(OH),D, Cholecalciferol administrat ion increased 25(OH)D in all groups, 1, 25(OH),D in postmenopausal Cur acao women and PTH in postmenopausal Curacao women and premenopausal D utch women, Serum and urinary Ca and phosphate concentrations did not change, There were no response differences between 10 and 20 mu g dose s, Oral cholecalciferol administration (either 10 or 20 mu g/d) to wom en living at northern latitudes in late winter/early spring increased 25(OH)D levels to the baseline levels of elderly people living in the tropics.