Strategies are needed to prevent functional decline and falls in the senior population.
Vitamin D deficiency has been associated with poor physical performance; meanwhile, impaired lower extremity function is a major risk factor for falls, injuries and a loss of autonomy.
As the senior population grows, attention is turning to ways to prevent functional decline and its undesirable and costly consequences, such as the loss of mobility and the need for hip replacements.
Vitamin D supplementation has been proposed as part of this strategy, based on evidence that muscle weakness is a feature of clinical vitamin D deficiency.
Previous research has suggested that the vitamin D receptor is expressed in human muscle tissue, and that its activation in muscle can help promote muscle fiber reactions relevant to the prevention of falls.
Does Vitamin D really help?
However, there is a lack of evidence proving the usefulness of vitamin D supplementation in preventing functional decline and falls.
To investigate whether high-dose vitamin D could help lower the risk of functional decline, Dr. Heike A. Bischoff-Ferrari, of the University Hospital in Zurich, Switzerland, and coauthors conducted a 1-year, randomized clinical trial involving 200 men and women aged 70 or older who had previously fallen. At the beginning of the study, 58% of the participants were deficient in Vitamin D.
Participants were divided into three study groups: 67 people in a low-dose control group who received 24,000 IU of vitamin D3 per month, 67 people who received 60,000 IU of vitamin D3 per month, and 66 people who received 24,000 IU of vitamin D3 plus calcifediol per month.
The study measured improvement in lower extremity function, achieving 25-hydroxyvitamin D levels of at least 30 ng/mL at 6 and 12 months, and reported falls.
Higher dose, more falls
Findings showed that doses of 60,000 IU and 24,000 IU plus calcifediol were more likely to result in 25-hydroxyvitamin D levels of at least 30 ng/mL but they were associated with no benefit on lower extremity function.
During the 12-month treatment period, 60.5% of the participants experienced a fall. These included 66.9% of those taking 60,000 IU and 66.1% of those taking 24,000 IU plus calcifediol. In contrast, only 47.9% of those taking 24,000 IU experienced a fall.
In other words, the participants taking 60,000 IU had an average 1.47 higher chance of falling, and those taking 24,000 IU plus calcifediol had a 1.24 increased risk, while those taking 24,000 IU had a lower than average chance of falling, at 0.94.
The researchers note that the higher dose confers "no benefit on the prevention of functional decline and increased falls in seniors 70 years and older with a prior fall event."
"High monthly doses of vitamin D or a combination of calcifediol may not be warranted in seniors with a prior fall because of a potentially deleterious effect on falls."
The team also calls for further research to confirm the findings.
In a linked commentary, Dr. Steven R. Cummings, of the California Pacific Medical Center Research Institute in San Francisco, and coauthors note that due to the lack of evidence that higher levels of vitamin D reduces the risk of falls and fractures, and that it may even increase the risks, the Institute of Medicine's (IOM) recommendations regarding Vitamin D intake should be followed.
These state that from the age of 70 years, people should have a total daily intake of 800 IU of vitamin D without routine measurement of serum 25 (OH)D levels.
They also recommend getting vitamin D and other vitamins from a balanced diet including foods that naturally contain them.
Medical News Today recently reported that low vitamin D levels may impact heart health.