A link between low vitamin D and brain small vessel disease

This study looked at the link between low vitamin D and cerebral (brain) small vessel disease in patients with a stroke. The authors concluded that patients with low vitamin D levels had a greater burden of cerebral small vessel disease.

Cerebral small vessel disease (cSVD) refers to problems associated with small blood vessels in the brain. It includes the following: lacunar infarcts (LIs, blocked blood flow to one of the small arteries in the brain), cerebral microbleeds (CMBs, bleeding from small vessels in the brain), white matter lesions (WMLs, abnormal tissue in the brain), and enlarged perivascular spaces (EPVs, fluid-filled spaces surrounding vessels in the brain). 

cSVD is generally associated with aging and is detected by abnormal MRI scans. It is also associated with a decline in cognitive (memory and thinking) function and worse recovery following stroke. Vitamin D deficiency is associated with cardiovascular diseases including stroke. It is possible that vitamin D deficiency is linked to cSVD.

The study included 234 patients who have had one stroke. The patients had MRI scans on their brains, which were then analyzed. The authors included markers for cSVD which were LIs, CMBs, WMLs, and EPVs.

8.5% of patients had no markers of cSVD and 3.8% of patients had all four markers. 42.3% of patients had 2 different markers of cSVD.

Vitamin D levels were separated into 4 groups, very low, low, medium and high. Patients with very low levels of vitamin D were 3.31 times more likely to have severe WMLs compared to those with high levels of vitamin D. These patients were also 2.35 times more likely to have severe EPVs. Finally, these patients were 3 times more likely to have increased cSVD burden on their MRI scans than those with high vitamin D levels.

The authors concluded that vitamin D deficiency is associated with cSVD in patients with stroke.

This study only included a small subset of patients, those who presented with first-ever stroke. The authors did not take into account other factors that might influence patient vitamin D levels such as outdoor physical activity, sun exposure, diet, and thyroid function. Vitamin D level was only assessed once in each patient during the study.

Discuss with your doctor if you have concerns regarding vitamin D levels.