Could High Doses of Vitamin D Lead to Falls?

Vitamin D deficiency has been associated with poor physical performance, and many patients who experience falls have low vitamin D levels.

Some researchers have suggested that high-dose vitamin D supplementation may restore some functionality, if not physical prowess. Several studies have also examined high-dose vitamin D’s effectiveness in lowering the risk of functional decline, but they produced mixed results.

Researchers recently conducted a new, well-structured study to determine whether improved vitamin D levels would correlate with fewer falls. They designed a double-blind, randomized clinical trial and enrolled 200 community-dwelling men and women aged 70 years and older who reported a previous fall.

The participants’ average age was 78 years, and 58% (116) of them were vitamin D deficient (<20 ng/mL) at baseline.

They were assigned to the following 3 groups and then followed for 1 year:

· A low-dose control group receiving 24,000 IU of oral vitamin D3 once monthly

· A group receiving 60,000 IU of vitamin D3 oral once monthly

· A group receiving 24,000 IU of oral vitamin D3 plus 300 mcg of calcifediol once monthly

Three key findings that pharmacists should review include:

Key Finding 1

Participants who received either 60,000 IU or 24,000 IU plus calcifediol were more likely to achieve 25-hydroxyvitamin D levels of at least 30 ng/mL than those in the low-dose arm.

Key Finding 2

All participants had sufficient mobility to use public transportation at the start of the study, but they had elevated risk of functional decline because of a previous fall. The best predictor of a future fall is a past fall.

Despite treatment for 1 year, all participants continued to have similar lower extremity function at the end of a year. The researchers saw no improvement, regardless of vitamin D levels.

Key Finding 3

Over the course of the study, each arm’s fall rate was different. Participants in the 2 arms that received higher doses of vitamin D were significantly more likely to fall than those in the control arm.

Approximately 66% of patients in the 60,000 IU and 24,000 IU plus calcifediol arms reported falls. Only 48% of patients in the control arm fell.

The researchers also looked at the mean number of falls. As vitamin D dose increased, so did falls. The mean number of falls for the control group was 0.94, but for the 60,000 IU and 24,000 IU plus calcifediol groups, the mean number of falls was 1.47 and 1.24, respectively.