Table 1 Baseline characteristics of patients in the included studies

Afzal et al. 2014 [14]

Prospective Cohort

Denmark

352

58

 ≤ 25 ng/mL

21

2

age, sex, month of blood sample, smoking status, body mass index, leisure time, work-related physical activity, alcohol consumption, income level, education, baseline diabetes mellitus, hypertension, cholesterol, HDL cholesterol, and creatinine

Littlejohns et al. 2014 [15]

Prospective Cohort

United States

1658

73.6 (4.5)

 ≤ 25 ng/mL

5.6

3

Age, season of vitamin D collection, education, sex, BMI, smoking, alcohol consumption, and depressive symptoms

Karakis et al. 2016 [16]

Prospective Cohort

United States

1663

72.4

 < 10 ng/mL

9

3

Age, gender, vascular risk factors (smoking, hypertension, diabetes, prevalent cardiovascular disease, and homocysteine), BMI, and vitamin D supplement use

Feart et al. 2017 [17]

Prospective Cohort

France

916

73.3

 ≤ 25 ng/mL

12

2

Gender, education, income, depressive symptomatology, number of drugs per day, apolipoprotein E ε4 allele, BMI, practice of physical exercise, diabetes, history of cardiovascular diseases and stroke, hypertension, hypercholesterolemia, hypertriglyceridemia, smoking status, and Mediterranean diet score

Licher et al. 2017 [18]

Prospective Cohort

Netherlands

6087

82.5 ± 8.6

 ≤ 25 ng/mL

13.3

2

Age, sex, season of blood collection, BMI, blood pressure, educational level, smoking, alcohol use, calcium serum levels, ethnicity, eGFR, TC, HDL, history of diabetes, heart failure, stroke, myocardial infarction, depressive symptoms, outdoor activity, and APOE-4 carrier status

Aguilar-Navarro et al. 2019 [19]

Cross sectional

Mexico

208

79 ± 1

 ≤ 20 ng/mL

NR

3

Age, sex and years of education