Vitamin D deficiency is not possible to correct with the nutritional vitamin D doses in postmenopausal women with decreased bone mineral density. The aim of study was to evaluated the effectivity and safety of 15000 IU/week vitamin D administrated in 52 postmenopausal women with osteopenia or osteoporosis. Patients were divided into two groups. Treated group was supplemented by calcium 0.5 g/d and 25-hydroxycholecalciferol 15000 IU/week and control group was supplemented by calcium and placebo for two months. Plasma calcium concentration did not change in the vitamin D treated group while it decreased (p < 0.001) in the control group. Neither calciuria nor fractional excretion of calcium changed during the treatment period. Plasma inorganic phosphate concentration did not change in any group, but urinary inorganic phosphate excretion increased in the vitamin D treated group (p < 0.001). The starting 25-hydroxycholecalciferol plasma concentrations were almost at the deficiency range in both groups. The 25-hydroxycholecalciferol plasma concentration increased substantially (p < 0.001) in the treated group, but it remained at the starting level in control group during the treatment period. Similar plasma concentration increase (p < 0.001) was apparent also in 1.25-dihydroxycholecalciferol. Plasma intact parathormone concentration did not change in the vitamin D treated patients, while it increased (p < 0.01) in the control group. None of the vitamin D treated women suffered from hypercalcemia and mild hypercalciuria was observed in one patient. In conclusion, the study presents an evidence on the effectiveness and safety of 15000 IU/week 25-hydroxycholecalciferol dosage schedule.

        Key words: Osteoporosis - Calcium -Vitamin D - 25-hydroxycholecalciferol - 1.25-dihydroxycholecalciferol