A major health concern for older populations is increased risk for falls. This is partly caused by reduced lower extremity function, prevention of which could save many injuries from occurring in older adults. Vitamin D has been thought to aid in lower extremity function and is especially believed to help with muscle weakness. To evaluate this, the researchers of this study conducted a double blind clinical trial to evaluate the effects of high-dose vitamin D in older adults. The study looked at 200 men and women with a low-trauma fall in the past year who were also 70 years and older. These 200 participants were separated into three study groups: one receiving 24,000 IU of vitamin D3 per month (normal dose), one receiving 60,000 IU of vitamin D3 per month, and one receiving 24,000 IU of vitamin D3 plus calcifediol per month. At the end of the study, the increase in 25-hydroxyvitamin D levels was evaluated for each group.
The results for the first group receiving 24,000 IU showed that the 25-hydroxyvitamin D levels increased by 11.7 ng/mL after 12 months. The second group receiving 60,000 IU increased its levels by 19.2 ng/mL. Finally, the third group receiving both the 24,000 IU and the calcifediol increased its 25-hydroxyvitamin D levels by 25.8 ng/mL after 12 months. The participants were also tested using the Short Physical Performance Battery (SPPB). This test assessed lower extremity function by evaluating walking speed, balance, and successive chair stands. When looking at the change in SPPB scores, it can be noted that there was no significant difference between the treatment groups. Further data collected from the study also evaluated the incidence of falls in the subjects. During the 12 month period of the study, 121 of the participants fell. The 60,000 IU group and the 24,000 IU group with calcifediol had significantly higher percentages of falls compared with the treatment group that only received the 24,000 IU of vitamin D3.
It was concluded that higher doses of vitamin D monthly do not provide benefit for the decline in lower extremity function. This was shown through the SPPB scores and the lack of improvement with higher doses. Also, high doses were shown to increase the number of falls in participants and, therefore, may be considered unsafe in older adults who have already experienced a fall.
I found this study to be interesting because we are often told how over the counter vitamins and herbals do not have much research behind them. I therefore chose to read this article to learn more information about vitamins. The study actually proved to me how little we seem to know about these supplements. The consensus on vitamin D that was used as the basis for this study was that it can improve muscle function. However, high doses of it actually seem to have done more harm than good. As a pharmacist, it is important to know this information when evaluating the medication regimen of an older adult. Doses of vitamin D should be monitored closely with someone who experiences falls, especially if they are taking other medications that may also contribute to more frequent falls.
Bischoff-Ferrari H, Dawson-Hughes B, Orav J, et al. Monthly high-dose vitamin D treatment for the prevention of functional decline: a randomized clinical trial. JAMA Intern Med. 2016; 176(2): 175-183.