Researchers at Turkey's Erenkoy Physical Medicine and Rehabilitation Hospital and Fatih Sultan Mehmet Education and Research Hospital conducted a randomised, double-blind study to investigate the effects of vitamin D supplementation on rehabilitation outcomes and balance in ischaemic stroke patients suffering from hemiplegia (paralysis of one side of the body).
Does D make a difference?
They recruited 72 patients with low vitamin D levels who had been hospitalised for hemiplegia rehabilitation and divided them equally into two groups: group A was injected with 300,000 IU of vitamin D, while group B was injected intramuscularly with saline, both before a three-month rehabilitation period.
All patients were tested at baseline and then the third month of the study, using Brunnstrom recovery staging (seven recognised stages of post-stroke recovery), a functional ambulation scale, a modified Barthel Index (to assess self-care and mobility in daily living, and the Berg balance scale (to objectively measure balancing ability).
The researchers then reported that by the end of the third month, the Berg balance scale results and modified Barthel index scores "significantly differed" between the two groups. On the other hand, Brunnstrom recovery staging and functional ambulation scale test results did not exhibit any marked difference between the groups.
They wrote: "The results of the Brunnstrom recovery staging for the upper extremity, hand, and lower extremity evaluations did not statistically significantly differ between Groups A and B.
"Although (the) modified Barthel Index did not significantly differ between the two groups at the beginning of the study, by the end of the 3rd month, a statistically significant difference was evident.
"The baseline and third-month statistics of the functional ambulation scale did not significantly differ between the groups."
They further stated that these results were consistent with those of previous research on the link between vitamin D and quality of life and ambulation ability — while there were considerable improvements in daily living activities, no such improvements in ambulation were observed.
Larger size needed
The researchers did say, however, that the study's "most important limitation" was its small sample size, which prevented them from making any generalisations.
The short follow-up period of three months was also a limitation, as a long-term comparison of results could have offered a wider perspective.
There have been studies on the effects of vitamin D supplementation on cognitive function and muscle strength — two areas of health affected by stroke — but results have been contradictory, and research focused on vitamin D supplementation's impact on ischaemic stroke rehabilitation outcomes has been somewhat less extensive.
The researchers concluded: "This study supports that vitamin D supplementation has positive effects on the improvement of balance and activities of daily living in patients having hemiplegia due to ischaemic stroke who have low levels of vitamin D.
"However, the effects on motor healing and ambulation could not be clearly demonstrated."
Source: The Journal of Physical Therapy Science
"A randomized, double-blind study to assess if vitamin D treatment affects the outcomes of rehabilitation and balance in hemiplegic patients"
Authors: Aylin Sari, et al.