TABLE 1.
Characteristics of the studies for standardization of serum 25(OH)D concentrations in European populations1
| Study [year(s) of study] (ref) | Region/country (latitude) | N | Age, y | Sex, female:male, % | Ethnicity, white:nonwhite, % | Season of sampling, % | Original 25(OH)D method |
| HELENA [2006–2007] (15, 16) | 10 EU Centres2 (35–59°N) | 1006 | 14.7 ± 1.2 (12.5–17.4)3 | 53.2:46.8 | 93.3:4.84 | Winter: 21.9 | IDS ELISA |
| Spring: 45.6 | |||||||
| Summer: 9.0 | |||||||
| Autumn: 23.5 | |||||||
| OPUS School Meal Study [2011–2012] (17, 18) | Eastern Denmark (54–55°N) (regionally representative) | 7795 | 10.0 ± 0.6 (8.4–11.6)5 | 47.8:52.25 | 94.7:5.35 | Baseline visit5 | DiaSorin Liaison |
| Winter: 0.0 | |||||||
| Spring: 2.7 | |||||||
| Summer: 97.3 | |||||||
| Autumn: 0.0 | |||||||
| Tromsø Study: Fit Futures [2010–2011] (19–21) | Tromsø/Norway (69°N) (regionally representative) | 890 | 16.0 ± 1.0 (15.0–18.0) | 46.6:53.4 | 97.1:1.94 | Winter: 45.7 | LC-MS/MS |
| Spring: 24.2 | |||||||
| Summer: 0.0 | |||||||
| Autumn: 30.1 | |||||||
| HGS [2007–2009] (22) | Athens, Crete, Thessaloniki/Greece (35–40°N) (regionally representative) | 806 | 11.2 ± 0.6 (9.4–13.7) | 52.2:47.8 | 98.5:1.5 | Winter: 21.3 | Roche Elecsys |
| Spring: 51.1 | |||||||
| Summer: 1.9 | |||||||
| Autumn: 25.7 | |||||||
| INNS [2005–2007] (23) | Athens/Greece (37°N) (regionally representative) | 222 | 4.5 ± 0.6 (3.0–5.9) | 46.0:54.0 | 99.1:0.9 | Winter: 37.4 | NA (measured de novo) |
| Spring: 36.5 | |||||||
| Summer: 0.4 | |||||||
| Autumn: 25.7 | |||||||
| Cork BASELINE Birth Cohort Study [2008–2011] (24) | Cork/Ireland (51°N) | 742 | 2.1 ± 0.1 (1.9–2.8) | 47.2: 52.8 | 98.9: 1.1 | Winter: 22.2 | NA (measured de novo) |
| Spring: 24.7 | |||||||
| Summer: 22.2 | |||||||
| Autumn: 30.9 | |||||||
| KiGGS [2003–2006] (25) | Germany (47–55°N) (nationally representative) | 10,015 | 9.5 ± 4.6 (1–17) | 49.0:51.0 | NA | Winter: 24.4 | DiaSorin Liaison |
| Spring: 21.9 | |||||||
| Summer: 24.3 | |||||||
| Autumn: 29.4 | |||||||
| NDNS: Rolling Program Years 1–4 [2008–2012] (26) | United Kingdom (50–59°N) (nationally representative) | 5116 | 11.6 ± 4.7 (1–18)6 | 45.4:54.66 | 87.7:12.36 | Winter: 25.46 | DiaSorin Liaison |
| Spring: 25.6 | |||||||
| Summer: 23.7 | |||||||
| Autumn: 25.24 | |||||||
| NDNS: Rolling Program Years 1–4 [2008–2012] (26) | United Kingdom (50–59°N) (nationally representative) | 9776 | 50.5 ± 16.0 (19–91)6 | 53.4:46.66 | 93.2:6.86 | Winter: 24.16 | DiaSorin Liaison |
| Spring: 26.0 | |||||||
| Summer: 25.3 | |||||||
| Autumn: 24.74 | |||||||
| DEGS [2008–2011] (27, 28) | Germany (47–55°N) (nationally representative) | 6995 | 50.6 ± 16.6 (18–79) | 52.0:48.0 | NA | Winter: 22.7 | DiaSorin Liaison |
| Spring: 24.8 | |||||||
| Summer: 20.9 | |||||||
| Autumn: 31.6 | |||||||
| Tromsø Study–6th Survey [2008] (29–31) | Norway (69°N) (regionally representative) | 12,817 | 57.5 ± 12.6 (30–87) | 46.7:53.3 | 100.0:0.0 | Winter: 24.6 | Roche ECLIA |
| Spring: 21.4 | |||||||
| Summer: 16.3 | |||||||
| Autumn: 37.7 | |||||||
| NHS [2006–2007] (32) | Netherlands (52°N) (regionally representative) | 2625 | 53.4 ± 6.7 (40–66) | 53.6:46.4 | 95.8:4.2 | Winter: 26.2 | NA (measured de novo) |
| Spring: 14.2 | |||||||
| Summer: 26.3 | |||||||
| Autumn: 33.3 | |||||||
| LASA [2009] (33) | Netherlands (52°N) (nationally representative) | 915 | 71.4 ± 7.7 (61–99) | 53.4:46.6 | 96.8:3.04 | Winter: 7.5 | DiaSorin Liaison |
| Spring: 28.8 | |||||||
| Summer: 40.2 | |||||||
| Autumn: 22.84 | |||||||
| AGES-Reykjavik [2002–2006] (34) | Iceland (64°N) (regionally representative) | 5519 | 76.6 ± 5.6 (66–96) | 57.3:42.7 | 100.0:0.0 | Winter: 25.5 | DiaSorin Liaison |
| Spring: 26.5 | |||||||
| Summer: 15.1 | |||||||
| Autumn: 32.9 | |||||||
| Finnish Migrant Health and Wellbeing Study (Maamu) [2010–2012] (35, 36) | Finland (60–63°N) (representative of the immigrant populations in 6 Finnish cities) | 1310 | 37.0 ± 12.0 (18–64) | 56.5:43.5 | Ethnic7 | Winter: 32.2 | Architect chemiluminscent |
| Spring: 32.5 | |||||||
| Summer: 12.4 | |||||||
| Autumn: 23.9 |
AGES, Age, Gene/Environment Susceptibility; DEGS, German Health Interview and Examination Survey for Adults; EU, European Union; HELENA, Healthy Lifestyle in Europe by Nutrition in Adolescence; HGS, Healthy Growth Study; INNS, Infant’s Nourishment and Nutritional Status; KiGGS, German Health Interview and Examination Survey for Children and Adolescents; LASA, Longitudinal Aging Study Amsterdam; LC-MS/MS, liquid chromatography–tandem mass spectrometry; NA, not applicable; NDNS, National Diet and Nutrition Survey; NHS, New Hoorn Study; OPUS, Optimal well-being, development and health for Danish children through a healthy New Nordic Diet; ref, reference; 25(OH)D, 25-hydroxyvitamin D.
Athens (Greece), Dortmund (Germany), Ghent (Belgium), Heraklion (Greece), Lille (France), Pecs (Hungary), Rome (Italy), Stockholm (Sweden), Vienna (Austria), and Zaragoza (Spain).
Mean ± SD; range in parentheses (all such values).
Overall percentage <100% as data not reported for some subjects.
OPUS sample at 3-mo visit: n = 386; female:male: 46.9%:53.1%; white:nonwhite: 93.3%:6.7%; sampled in winter, spring, summer, autumn: 80.9%, 12.4%, 0%, and 6.7%, respectively.
The NDNS was of individuals aged ≥1.5 y, but for this work, to allow comparison with other children and adult/older adult populations, the sample was stratified into 1–18 and >19 y. NDNS total population: n = 1488; female:male, 53.4%:46.6%; age range, 1.5–91 y; white:nonwhite: 91.3%:8.7%; sampled in winter, spring, summer, autumn: 24.5%, 25.9%, 24.7%, and 24.9%, respectively.
In total, 34.0%, 27.8%, and 38.2% were of Russian-speaking, Somali, and Kurdish immigrants, respectively.