Rates of bone loss in postmenopausal women randomly assigned to one of two dosages of vitamin D.

We conducted a study to determine whether increasing vitamin D intake above the recommended dietary allowance (RDA) of 5.0 micrograms (200 IU)/d reduces bone loss in healthy postmenopausal women residing at latitude 42 degrees N. In this double-blind, randomized 2-y trial, we enrolled 247 healthy ambulatory postmenopausal women who consumed an average of 2.

Effect of vitamin D supplementation on wintertime and overall bone loss in healthy postmenopausal women.

Objectives: To determine whether relative vitamin D deficiency during the winter months contributes to age-related bone loss and whether rates of change in hard- and soft-tissue mass vary during the year.

Design: Double-blind, placebo-controlled, 1-year trial in 249 women in which equal numbers of women were randomized to either placebo or 400 IU of vitamin D daily. All women received 377 mg/d of supplemental calcium largely as calcium citrate malate.