Table 2.

Effects of low vitamin D on stroke outcomes.

Patients with vitamin D deficiency	Comorbid conditions/ secondary outcomes	Cardiovascular risk /Stroke incidence
Patients with low serum 25-(OH)D	Metabolic syndrome	Increased cardiovascular risk in patients (4, 95)
Children with 25(OH)D concentrations <30 ng/mL	Severe obesity	Increased cardiovascular risk (8)
Low plasma levels calcidiol (vitamin D metabolite)	Sun exposure, coronary artery disease, and hypertension	Development of acute ischemic events (acute coronary syndrome, stroke, or transient ischemic attack) (8)
Vitamin D deficiency with serum 25(OH) vitamin D levels <20 ng/mL	Poor health behaviors, comorbid health conditions, and potential biological mediators	Higher risk of cerebrovascular and cardiovascular events such as heart failure, myocardial infarction, stroke, or cardiovascular death (11, 12, 96)
25(OH)D deficiency [defined as serum 25(OH)D levels <20 ng/mL]	Smoking status, hypertension, diabetes, elevated low-density lipoprotein cholesterol, hypertriglyceridemia, low high-density lipoprotein cholesterol, chronic kidney disease	Increased risk of cardiovascular disease (13)
25-dihydroxyvitamin D (25-OH D) levels 25-OH D deficiency (<15 ng/mL, <10 ng/mL)	n/a	Increase in cardiovascular risk (15)
Low levels of 25-hydroxyvitamin D (25[OH]D)	Cardiovascular, musculoskeletal, infectious, autoimmune, and malignant diseases	Cerebrovascular disease and stroke (17)
Low 25(OH)VitD	Air pollution and low sunlight exposure along with severe malnutrition	High risk of cardiovascular disease and stroke (18, 47, 58)
Low vitamin D status (Meta-analysis)	n/a	Increased risk of ischemic stroke not hemorrhagic stroke (19)
25(OH)D concentrations deficient (<10 ng/mL) and insufficient (10–20 ng/mL)	Adverse effects on neurocognitive health and stroke (with and without dementia symptoms)	Cerebrovascular disease and Cardiovascular disease (CVD) stroke (57, 97)
Low 25-hydroxyvitamin D levels (25[OH]D)	Diabetes mellitus, hypertension, and cancer	CVD with 26% increased rate of all-cause mortality (65)
Low serum 25-dihydroxyvitamin D levels	Musculoskeletal health	Acute stroke (59, 59)
Low 25-hydroxyvitamin D (25[OH]D) (<12 ng/mL)	Elevated cardiovascular disease risk	29% higher CVD risk and 3.3-fold elevated risk of ischemic stroke while higher vitamin D levels were significantly associated with reduced risk of stroke (60, 66)
Low levels of 25(OH)D and 1,25(OH)2D	History of previous cerebrovascular disease events	Increased ischemic and hemorrhagic strokes (61)
Low dietary vitamin D intake or serum 25-hydroxyvitamin D deficiency	Age, calories, body mass index, hypertension, diabetes, smoking, physical activity, serum cholesterol, alcohol intake and low high-density lipoprotein cholesterol	Increased all stroke, thromboembolic ischemic stroke (25, 64)
Deficiency of 25-hydroxyvitamin D	Cardiovascular disease events and mortality	The risk of fatal stroke was greater in blacks compared with whites (67).
Low 25-hydroxyvitamin D concentrations	There were no statistically significant differences in the association of stroke in black vs. white participants	Increased risk of stroke in patients with 25-hydroxyvitamin D <20 ng/mL (68)
Low serum 25-hydroxyvitamin D [25(OH)D]	Atherosclerosis Risk in Communities	The lowest quintile of 25(OH)D (<17.2 ng/ml) was associated with higher stroke risk (69)
Non-diabetic with vitamin 25-hydroxyvitamin D (25(OH) D) deficiency	n/a	Increased poor functional outcome events in Chinese non-diabetic stroke individuals (70)
Low 25-hydroxyvitamin D [25(OH)D]	Hemodialysis, diabetes	Severe vitamin D deficiency was strongly associated with stroke, cardiovascular events, and mortality (71, 98)
Low serum 25(OH)D	Multivariable analyses showed that the risk for a poor 90-day outcome doubled with each 10-ng/mL decrease in serum 25(OH)D	Low levels associated with large volume infarcts Higher serum 25(OH)D concentration was associated with smaller infarct volumes (20)
Low serum 25(OH)D level. The mean 25(OH)D level was 47.2 ± 31.7 nmol/l, and most patients met vitamin D deficient status (<50 nmol/l)	Vascular risk factors	Increased stroke severity in patients (20, 31)
Low serum 25-Hydroxyvitamin D (25(OH)D)	Intravenous thrombolysis	Worse functional acute ischemic stroke outcomes (32)
The mean level of 25(OH)D was significantly lower in the chronic group than in the subacute group (12.3 vs. 16.3 ng/mL.	Patients with a history of total parenteral nutrition had lower 25(OH)D levels than subjects who had enteral nutrition	Onset of stroke (33)
Low concentrations of plasma 25-hydroxyvitamin D (25(OH)D) and genetic variants in DHCR7/ CYP2R1	Cardiovascular disease (CVD) risk, myocardial infarction, high blood pressure, hypertension, and	Increased risk of ischemic stroke (73, 74)
Low serum levels of 25(OH) D	Increased risk of cardiovascular disease	Levels were observed to be prognostic markers of cardiovascular disease and all-cause mortality in Chinese patients with ischemic stroke or risk of recurrent stroke (21, 22)
25(OH)D levels	High inflammatory markers	Poor short-term outcome in acute ischemic stroke patients as indicated by modified Rankin scale (36)
Insufficiency of 25(OH) vitamin D was observed after birth in 70% of infants	Lower circulating anti-inflammatory IL-17E	Higher risk of hypoxic-ischemic encephalopathy (99)
25(OH)D deficiency	Hypertension	Stroke severity was worse with National Institutes of Health Stroke Scale (NIHSS) score (37)
Vitamin D deficiency	Cognitive decline was observed	Increased acute ischemic stroke occurrence (39)
Decreased levels of 25-hydroxyvitamin D (25-OH-D)	Cardiovascular risk	Ischemic stroke with increased risk of mortality (100)
Serum 25-hydroxyvitamin D [25(OH)D] levels	Early neurological deterioration	Higher risk of acute ischemic stroke (101)
mean 25(OH)D level was lower <25.7 nmol/l	Age <75 years	Higher mortality in stroke (40)
Lower serum levels of 25(OH) D. (24-month follow-up study in China involving 220 stroke population)	n/a	Patients had recurrence of ischemic stroke with high mortality (41).
High 25(OH)D levels	Improve cognitive function	Stroke patients showed improved neurological function (23)
Vitamin D deficiency	Increase in arterial stiffness, widening of pulse pressure, atherosclerosis, cardiovascular morbidity and mortality	Increased risk of stroke occurrence (27)
Low serum 25(OH)D levels	Deep vein thrombosis (DVT)	Ischemic stroke (28)
Low median 25(OH)D level i.e., 39.2 nmol/L	Cerebral small vessel disease (cSVD)	Minor ischemic stroke or transient ischemic attack were included (30)
386 patients, with low serum 25(OH)D levels	n/a	Increased incidence of stroke (102)
Low intake of vitamin D and certain flavonoids	Age, gender, smoking and functional capacity	Increased acute myocardial infarction and stroke (42)
Dietary vitamin D intake (965 to 970 person-years on follow-up found 1,514 stroke and 702 coronary heart disease patients)	Stroke, intraparenchymal hemorrhage, coronary heart disease	Intake inversely associated with mortality from stroke (43)
Non-blinded randomized controlled trial conducted in ischemic stroke patients with low serum 25(OH)D levels	n/a	Vitamin D replenishment will improve the stroke outcome (75)
Randomized controlled trial in 73 patients assessing vitamin D & calcium on ischemic stroke outcomes	n/a	Benefit observed in ischemic stroke patients (76)
Serum 25-hydroxyvitamin D [25(OH)D] levels ≤ 20 ng/mL	Overweight African-Americans age 13–45 years	Arterial stiffness improved with vitamin D3 supplementation in vitamin D deficiency (78)
Serum 25-hydroxyvitamin D [25(OH)D] levels not measured in total of 2,690 patients who had a first episode of non-fatal ischemic stroke	Age 40–89 years old	Calcium supplementation along with vitamin D was not associated with an increased risk of ischemic stroke (89)