“Vitamin D deficiency is highly prevalent due to lifestyle and environmental factors which limit sunlight induced vitamin D production in the skin. This "pandemic" of vitamin D deficiency is of concern because low levels of 25-hydroxyvitamin D (25[OH]D) have been associated with cardiovascular, musculoskeletal, infectious, autoimmune and malignant diseases.
Epidemiological studies have largely but not consistently shown that vitamin D deficiency is a risk factor for stroke. This is supported by associations of low 25(OH)D levels with cerebrovascular risk factors, in particular with arterial hypertension. Vitamin D has also been shown to exert neuroprotective, neuromuscular and osteoprotective effects which may reduce cognitive and functional impairments in poststroke patients”
Further research reported that patients with low vitamin D level had larger areas of infarct when compared to those with normal vitamin D levels. For each 10 ng/ml decrease in vitamin D level, stroke recovery after three months decreased by half.
Although the studies are small in size and therefore it is deemed to be too early to draw conclusions, the research does urge patients to discuss their need for vitamin D supplementation with their physician.