Long-term high-dose vitamin D supplementation also showed no effect in reducing the risk of falls in seniors.
The above is based on the findings of the D-Health Trial – a randomised, double-blind, placebo-controlled study conducted in Australia.
Involving over 21,000 seniors aged 60 to 84, the trial randomised them to monthly doses of either 60,000 IU of vitamin D or placebo for an average of 4.3 years to a maximum of five years.
The number of falls was recorded using annual surveys and a three-month diary.
Findings of the study were recently published in The Journal of Cachexia, Sarcopenia, and Muscle, where the annual surveys of 15,416 trial participants and three-month diary of 2,200 participants were analysed.
The D-Health Trial, led by Professor Rachel Neale from the QIMR Berghofer Medical Research Institute, is the world’s second-large study that looks at the use of high-dose vitamin D supplementation and its effects on different health parameters, such as all-cause mortality and cancer incidence.
In February, the researchers published on The Lancet Diabetes & Endocrinology on how a single dose of 60,000IU of vitamin D each month did not reduce the overall risk of acute respiratory tract infection. However, it could slightly reduce the duration of infection symptoms.
In its latest findings, the researchers found that the high dose of vitamin D intake did not reduce the risk of falls – which is in contrary to their hypothesis.
Based on the annual survey results, a similar percentage of participants in both placebo and vitamin D groups said they experienced at least a fall in the month prior to answering the survey.
Specifically, six per cent of the participants in the vitamin D group reported experiencing at least a fall in the annual survey, while the incidence rate was similar at 5.8 per cent in the placebo group.
In addition, 15.2 per cent in the vitamin D group said they experienced at least a fall in the three-month diary, while the figure was lower at 14.6 per cent in the placebo group.
BMI and other factors
Interestingly, the trial also found that the combination of normal BMI and high dose vitamin D would lead to a greater risk of falls.
For participants with a normal BMI - lower than 25 kg/m2 and were in the vitamin D group, 17.4 per cent reported experiencing at least a fall within a three-month period.
In contrast, the incidence rate was lower at 11.4 per cent for participants with normal BMI but were on placebo.
As for participants with BMI equivalent or greater than 25 kg/m2, there was no significant difference in the risk of falling regardless of vitamin D intake. The risk of falling was 14.1 per cent for the vitamin D group and 15.9 per cent for the placebo group.
On average, most of the participants experienced a single fall during the three-month period. In both groups, two participants recorded four falls over three months.
Other factors that increase the risk of fall included older age, worse overall health, worse quality of life, chronic pain and fair or poor memory.
Falls were also more common among women and in those who lived alone or had ever smoked.
The researchers said this was the first study to suggest that intermittent supplementation with high-dose vitamin D might increase the risk of falling in people with BMI less than 25 kg/m2, while having little effect in people with BMI that is equal to or greater than 25 kg/m2.
“In conclusion, our results do not support the use of monthly high-dose vitamin D supplementation for falls prevention.
“The evidence of increased risk in people with BMI less than 25 kg/m2 warrants further investigation, ideally through reanalysis of existing trials. In the meantime, caution should be used in prescribing high-dose vitamin D to older adults in the normal BMI range and who are vitamin D replete,” the researchers said.
Source: The Journal of Cachexia, Sarcopenia, and Muscle
Vitamin D supplementation and risk of falling: outcomes from the randomized, placebo-controlled D-Health Trial
Authors: Neale and et al