A recent randomized controlled trial published in JAMA Internal Medicine indicated that neither exercise nor vitamin D reduced falls in elderly women.
One out of every three older adults, those aged 65 or older, falls each year. About 20% of falls lead to injury requiring medical attention. Therefore, ways of prevention need to be utilized.
Strong evidence suggests that regular strength and balance training can reduce the risk of falling in older adults by up to 50%. Studies have also linked vitamin D to bone loss and a decreased the risk of fractures. However, research investigating the role of vitamin D in preventing falls and fractures has been inconsistent.
Researchers recently conducted a two year long randomized controlled trial to clarify the role of vitamin D and exercise in the prevention of falls among the elderly.
They enrolled 409 home-dwelling women, ages 70 to 80 years old living in Tampere, Finland. All participants had fallen at least once during the previous year, did not use vitamin D supplements, and had no contraindications to exercise.
The participants were randomly assigned to one of four groups: (1) placebo without exercise, (2) vitamin D without exercise, (3) placebo with exercise, and (4) vitamin D with exercise.
If the participants were enrolled into one of the two vitamin D groups, they received a daily vitamin D supplement of 800 IU for two years, whereas the placebo groups received a daily dummy pill for two years.
The participants in the exercise groups took part in progressive group training classes two times per week for the first year, and once a week for the last year. The classes focused on balancing, weight bearing, strengthening, and functional exercises. Those enrolled into the exercise groups were also instructed to complete a training program at home that took about 5 to 15 minutes and was performed on days when participants were not taking part in group training classes. The non-exercising groups were instructed to maintain their regular amount of physical activity.
The researchers were curious to find out whether vitamin D supplementation and exercise affected the number of falls, the number of injurious falls, bone mineral density (BMD), and physical functioning.
Here is what they found:
- By the end of the study, the vitamin D levels differed significantly between the vitamin D and placebo groups, with the former having an average level of 27.5 ng/ml and the latter having an average level 37.0 ng/ml.
- There were no differences in the rate of falls between the groups, indicating that vitamin D and exercise did not affect the rate of falls.
- When compared to the placebo without exercise group, the vitamin D without exercise group, placebo and exercise group, and vitamin D and exercise group experienced a reduction in injurious falls by 16%, 54%, and 62%, respectively.
- Femoral BMD declined in all groups, but the greatest decline was seen in the placebo without exercise group. The other three groups had significantly lower decline in femoral BMD compared to the placebo without exercise group (p = 0.02, 0.01, 0.04).
- The vitamin D and exercise group experienced significantly increased trabecular BMD at the tibia compared to the placebo without exercise group (P = 0.02).
- Exercise increased muscle strength, while vitamin D alone had no effect.
The researchers summarized their findings,
“This large randomized clinical trial of vitamin D and exercise showed that exercise training reduced injurious falls among home-dwelling older women, while the rate of falls was not affected by either treatment.”
This study had many strengths to acknowledge. First, it was a double-blind randomized controlled trial. This is the gold standard of research, because it helps prove causality and minimizes possible biases. Second, the study was of a long duration. Lastly, there was a significant difference in vitamin D levels between the vitamin D and placebo groups.
However, as with any study, there are a few limitations to consider in order to make sense of the results. The dose of vitamin D administered was relatively small. Some women withdrew from the study because the exercises were too challenging, meaning that the participants in this study were in good physical condition. Therefore, the results cannot be generalized to frail women.
Additionally, the placebo group maintained average vitamin D levels above 20 ng/ml, likely the minimum level needed to sustain bone. Since vitamin D would likely prevent falls by optimizing bone health, individuals with vitamin D levels already this high may not experience any further benefit.
The researchers noted, “…the baseline 25 (OH)D levels were likely too high to reveal all potential beneficial effects of the vitamin.”
Future trials will need to evaluate the effects of high-dose vitamin D supplementation in vitamin D deficient frail women to fully assess the effect of vitamin D in preventing falls.