Dietary Supplements Had No Impact on Preventing Second Fractures, Study Shows

Routine dietary supplementation with oral calcium and vitamin D3, either alone or in combination, had no impact on reducing the incidence of low-trauma secondary fractures in patients aged 70 years and older, a large randomized trial demonstrated.

The findings run counter to the conclusions of at least four published prevention trials, but “our study population was younger and less frail [than theirs] … and most were mobile and living in the community,” wrote the investigators, whose primary author was Adrian M. Grant, M.D., of the University of Aberdeen (Scotland). “Therefore, the participants in our trial might have been less likely to have vitamin D insufficiency and secondary hyperparathyroidism than those in the [other] trials.”

The investigators enrolled 5,292 patients aged 70 and older who were mobile before developing a low trauma fracture. They randomized the patients to one of four groups—800 IU daily oral vitamin D, 1,000 mg calcium, oral vitamin D combined with calcium, or placebo—and followed them for a median of 45 months (Lancet 2005;365:1621–8).

Every 4 months, study participants were asked via mailed questionnaire how many times in the last 7 days they had taken their tablets. They were also asked about general health status, hospital admission, falls, and possible adverse events. The investigators obtained information on further fractures and death from the questionnaires, from hospital staff, family and friends of study participants, and from national health statistics. Additional confirmation of radiologically confirmed fractures was sought from a second source.

The mean age of patients was 77, and most (85%) were women.

Of the 5,292 patients, 698 (13%) sustained a new low-trauma fracture. Of these, 183 (26%) were hip fractures.

Investigators observed no significant differences in the incidence of new, low-trauma fractures between patients who received calcium vs. those who did not (12.6% vs. 13.7%, respectively); between those who received vitamin D3 vs. those who did not (13.3% vs. 13.1%, respectively) or between patients who received combination treatment and those who received placebo (12.6% vs. 13.4%).

There were also no differences between the groups in terms of the incidence of all new fractures, fractures confirmed by radiography, hip fractures, death, number of falls, or quality of life.

The investigators concluded that the best pharmaceutical intervention to prevent secondary low-trauma fractures in the elderly is with “antiresorptive drugs, such as bisphosphonates, which have rarely been assessed in patients who have not been taking calcium or vitamin D,” they wrote. “This trial was not designed to directly address whether supplementation should be used as a primary-prevention measure or in those who live in a care-home environment. Clarification of the role of supplementation in these settings awaits the results of other trials.”