Table 1 Summary characteristics of studies included in the analysis of vitamin D deficiency and risk of AD
References | Year | Country | Study type | Participants | Average age (years) | OR | 95 % CI | 25(OH)D (nmol/L) | Adjustment |
|---|---|---|---|---|---|---|---|---|---|
Afzal [10] | 2014 | Denmark | Prospective cohort | 2384 | - | 1.25 | 0.95–1.64 | <25 | Age, sex, month of blood sample, smoking status, body mass index, leisure time and work-related physical activity, alcohol consumption, income level, education, baseline diabetes mellitus, hypertension, cholesterol, high-density lipoprotein cholesterol, and creatinine |
Afzal [10] | 2014 | Denmark | Prospective cohort | 4087 | - | 1.12 | 0.90–1.4 | 25–50 | Age, sex, month of blood sample, smoking status, body mass index, leisure time and work-related physical activity, alcohol consumption, income level, education, baseline diabetes mellitus, hypertension, cholesterol, high-density lipoprotein cholesterol, and creatinine |
Littlejohns [9] | 2014 | UK | Prospective cohort | 1615 | 73.6 ± 4.5 | 2.22 | 1.02–4.83 | <25 | Age, season of vitamin D collection, education, sex, BMI, smoking, alcohol consumption, and depressive symptoms |
Littlejohns [9] | 2014 | UK | Prospective cohort | 1615 | 73.6 ± 4.5 | 1.69 | 1.06–2.69 | 25–50 | Age, season of vitamin D collection, education, sex, BMI, smoking, alcohol consumption, and depressive symptoms |
Buell [12] | 2010 | USA | Cross-sectional | 318 | 73.5 ± 8.1 | 2.65 | 0.99–7.16 | ≤50 | Age, race, sex, body mass index, and education, kidney function, multivitamin use, season, diabetes, hypertension, plasma homocysteine, and ApoE allele status |