In a long-term follow up of the Women’s Health Initiative (WHI), researchers found that calcium plus vitamin D supplementation was associated with a decreased risk of vertebral fractures.

Research at the annual meeting of the American Society for Bone and Mineral Research reported that during the 12 year follow-up of 29,862 women, there was a 13% decrease in risk for vertebral fractures with calcium and vitamin D use.

The original WHI trial assessed whether 1,000 mg calcium and 400 IU vitamin D per day versus placebo reduced the risk of hip fracture and colorectal cancer among participants ages 50 to 79. The participants were followed for 7 years. After the intervention period, the authors reported supplementation was associated with a non-significant decrease in hip, vertebral, and total fractures.

After the intervention phase, participants were asked if they would like to continue in an extension phase of the trial, 29,862 agreed to participate.

During the additional 5 year follow-up, the annual rate of clinical vertebral fractures was 0.36% for the supplement group and 0.43% for the placebo group. The rate for total fractures was 3.31% versus 3.30 in the supplement and placebo groups respectively.

The researchers also found a non-significant decrease in risk for invasive colorectal cancer among supplement users, and slightly increased risk for breast cancer (p=0.06) among those who entered the trial with vitamin D intake in excess of 600 IU/day.

However, vitamin D supplement use displayed a protective effect for early stage breast cancer patients. No effects were observed for cardiovascular events or total mortality during the 5 year extension.

Among women who reported taking at least 80% of the study drug, there was a significant (23%) decrease for hip fracture.

The authors recognize limitations, including lack of treatment adherence as well as self-reported fractures (besides hip).

Read the full story here: Calcium and vitamin D cut spine fractures. MedPage Today.