Changes in vitamin-D metabolites and parathyroid hormone in plasma following cholecalciferol administration to pre- and postmenopausal women in the Netherlands in early spring and to postmenopausal women in Curaçao.

To study the effect on plasma 25-hydroxycholecalciferol (25(OH)D), 1,25-dihydroxycholecalciferol (1,25(OH)2D) and parathyroid hormone (PTH) we supplemented premenopausal (aged 30 (SD 7) years) and postmenopausal (aged 61 (SD 2) years) white women living in The Netherlands in late winter/early spring, and elderly black and white women (aged 75 (SD 6) years) living in Curaçao (Dutch Antilles) with either 10 or 20 micrograms cholecalciferol/d for 4, 5 and 9 weeks respectively. Baseline plasma 25(OH)D concentration of Dutch women was lower than that of Curaçao women. Postmenopausal Dutch women had a higher PTH concentration in plasma than premenopausal Dutch and postmenopausal Curaçao women. There were no differences in plasma 1,25(OH)2D. Cholecalciferol administration increased 25(OH)D in all groups, 1,25(OH)2D in postmenopausal Curaçao women and PTH in postmenopausal Curaçao women and premenopausal Dutch women. Serum and urinary Ca and phosphate concentrations did not change. There were no response differences between 10 and 20 microgram doses. Oral cholecalciferol administration (either 10 or 20 micrograms/d) to women 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.

Vitamin D supplementation of post-menopausal women in Curacao, and pre- and post-menopausal women in the Netherlands - abstract

Pre- and post-menopausal white women living in The Netherlands in late winter/early spring and black and white post-menopausal women living in Curacao were supplemented with either 400,800 and 2x400 IU vitamin D (3)/day or placebo for 4, 5, or 9 weeks. Baseline plasma 25-hydroxyvitamin D [25(OH)D] of Dutch women was lower than that of Curacao women. Post-menopausal Dutch women had higher parathyroid hormone (PTH) than pre-menopausal Dutch and post-menopausal Curacao women. There were no differences in 1,25-dihydroxyvitamin D [1,25(OH)2D]. Vitamin D supplementation increased 25(OH)D levels in all groups, PTH and 1,25(OH)2D in post-menopausal Curacao women, and PTH in pre-menopausal Dutch women. Serum and urinary calcium and phosphate did not change. There were no response differences between 400 and 800 IU daily doses, or 800 and 2x400 IU doses. Oral vitamin D supplementation raises late winter/early spring plasma 25(OH)D of women living at high latitudes to baseline levels encountered in the tropics (AU)