Characteristics at randomization in the entire cohort, and in subgroups defined by treatment allocation and by use of personal calcium or vitamin D.

Data are mean (SD) or %. HRT- hormone status. CaD- randomized to calcium plus vitamin Da Women not using personal calcium or vitamin D supplements at randomizationb Women from the placebo group who were either using both personal calcium and vitamin D or were not using either of these supplements at randomization.c all data are at randomization except for medical history and smoking status which are at entry to Women’s Health Initiative clinical trials programme. 91% of participants in the calcium plus vitamin D trial entered the trial at their first annual visit in the clinical trials programme and the remainder at their second annual visit.Characteristics at randomization in the entire cohort, and in subgroups defined by treatment allocation and by use of personal calcium or vitamin D.