Prevention of femoral and lumbar bone loss with hormone replacement therapy and vitamin D, in early postmenopausal women:: A population-based 5-year randomized trial

The long term effects of hormone replacement therapy (HRT) and vitamin D-3 (Vit D) on bone mineral density (BMD) were studied. A total of 464 nonosteoporotic early postmenopausal women from the Kuopio Osteoporosis Study (n = 13100) were randomized to four groups: 1) HRT (sequential combination of 2 mg estradiol valerate and 1 mg cyproterone acetate, 2) Vit D-3 (300 and 100 IU/day during the fifth year), 3) HRT and Vit D combined, and 4) placebo. Lumbar (L2-L4) and femoral neck BMD were determined by dual x-ray absorptiometry (DXA) at baseline and after 2.5 and 5 yr of treatment. Intention to treat analysis (n = 464) showed that after 5 yr, lumbar BMD remained unchanged in the HRT and HRT plus Vit D groups [+0.2% (P = 0.658) and +0.9% (P = 0.117), respectively], whereas lumbar BMD decreased by 4.6% in the VitD group and by 4.5% in the placebo group (P < 0.001 in both). The loss of femoral neck BMD was less in the HRT (-1.4%; P = 0.005) and HRT plus Vit D (-1.3%; P = 0.003) groups than in the Vit D and placebo groups (-4.3%; P < 0.001 in both). Among those 370 women who complied with the 5-yr treatment, the effect was more pronounced: lumbar BMD had increased by 1.5% in the HRT (P = 0.009) and by 1.8% in the HRT plus Vit D group (P = 0.005), with a plateau after 2.5 yr, whereas lumbar BMD had decreased in both theVit D and placebo groups (4.6% and 4.7%; P < 0.001, respectively). Femoral neck BMD decreased again less in the HRT (-0.4%) and HRT plus Vit D (-0.6%) groups than in the Vit D and placebo groups (-4.4% in both). This study confirms the positive long term effect of HRT on BMD also seen in intention to treat analysis. The data suggest that low dose vitamin D-3 supplementation does not prevent bone loss in healthy, nonosteoporotic, early postmenopausal women, and it confers no benefit additional to that of HRT alone.