Table 1.
Characteristics of prospective studies
| Author (year),reference study and year of conduct, quality score† | Country, study population | Gender, age (range or mean ± SD) (years) | Sample size (cases) | Baseline mean ± SD or % 25OHD, assay | 25OHD (nmol/L) comparison | Follow-up (years) | Primary endpoint: hypertension (mmHg) | RR (95% CI) | Confounders |
|---|---|---|---|---|---|---|---|---|---|
| Forman et al (2007),22 NHS2 1976–1990, HPFS 1986–1994, 5 | US, nurses and health professional | 34% male, 43–82 | 1,811 (407) | 62%<75, RIA | <37 vs ≥75 | 4 | Self-report | 0.31 (0.14–0.72) | Age, BMI, PA, ethnicity, diabetes status |
| Griffin et al (2011),23 MBHMS 1992–1993, 6 | US, general population | 100% female, 22–44 | 413 (104) | Mean =59, 81%<75, RIA | <80 vs ≥80 | 14 | BP ≥140/90 | 0.33 (0.12–0.99) | Age, % body fat, season, HTN treatment |
| Anderson et al (2010),24 IHS 2000–2009, 6 | US, general population | 25% male, 55±21 | 41,504 (2,490) | 64%<75, CLIA | <38 vs ≥75 | 1.3 | BP ≥140/90 | 0.62 (0.53–0.73) | Age, gender, season, HTN treatment, diabetes status |
| Jorde et al (2010),25 Tromsø Study 1994–2008, 7 | Norway, general population | 35% male, 50–74 | 1,268 (331) | 54±16, CLIA | <41 vs ≥63 | 14 | BP ≥140/90 | 0.99 (0.76 –1.28) | Age, gender, BMI, PA, season, HTN treatment |
| Kim et al (2010),26 Chungju city 2003–2007, 6 | Korea, general population | 38% male, 66±9 | 1,330 (851) | 47, CLIA | <20 vs ≥89 | 4 | BP ≥140/90 | 0.47 (0.27–0.82) | Age, gender, BMI, PA, season, HTN treatment |
| Margolis et al (2012),27 WHI 1993–1998, 5 | US, general population | 100% female, 50–79 | 2,153 (891) | 54%<50, CLIA | <34 vs ≥65 | 7 | BP ≥140/90 | 0.86 (0.60–1.23) | Age, BMI, PA, ethnicity, season, HTN treatment, diabetes status |
| Gagnon et al (2012),28 Aus-Diab 2000–2005, 7 | Australia, general population | 50% male, 25–75+ | 4,164 (1,291) | 68, RIA | <45 vs ≥85 | 5 | BP ≥130/85 | 0.71 (0.51–0.98) | Age, gender, PA, ethnicity, season, diabetes status |
| Wang et al (2013),29 PHS 1982–2009, 5 | US, physicians | 100% male, 40–84 | 660 (367) | 73±26, RIA | <50 vs ≥100 | 15 | Self-report | 0.94 (0.69–1.27) | Age, BMI, PA, ethnicity, season, HTN treatment, diabetes status |
| Ke et al (2013),30 ATBC 1985–1993, 4 | Finland, general population | 100% male (smokers), 50–69 | 1,957 (252) | 69%<50, RIA | <25 vs ≥80 | 4 | BP ≥140/90 | 1.00 (0.60–1.50) | Age, BMI, PA, season |
| van Ballegooijen et al (2014),31 MESA 2000–2002, 5 | US, general population | 47% male, 45–84 | 3,002 (1,229) | 31%<50, HPLC | <50 vs ≥75 | 9 | BP ≥140/90 | 0.81 (0.71–0.93) | Age, gender, BMI, PA, ethnicity, season, HTN treatment |
Note:
Quality score based on Newcastle–Ottawa Scale.
Abbreviations: NHS2, Nurses’ Health Study 2; HPFS, Health Professional Follow-up Study; MBHMS, Michigan Bone Health and Metabolism Study; IHS, Intermountain Healthcare System; WHI, Women’s Health Initiative; Aus-Diab, Australian Diabetes, Obesity and Lifestyle Study; PHS, Physicians’ Health Study; ATBC, Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study; MESA, Multi-Ethnic Study of Atherosclerosis; SD, standard deviation; 25OHD, 25-hydroxyvitamin D; RR, relative risk; CI, confidence interval; RIA, radioimmunoassay; US, United States; BMI, body mass index; PA, physical activity; BP, blood pressure; HTN, hypertension; CLIA, chemiluminescence immunoassay.