Table 4.
Vitamin D deficiency among adult immigrants in the Nordic countries, with strength of evidence
| Exposure/intervention | No. of participants (No. of studies) | Outcome variable (primary or secondary) | RR (95% CI) | Effect (95% CI) | No. of studies rated as A, B or C |
Strength of evidence (convincing, probable, limited-suggestive, limited-no conclusion) | Comments |
|---|---|---|---|---|---|---|---|
| Vitamin D deficiency in the adult general population, women |
N=2,279 ( immigrants n=1,104, indigenous n=1,064, country of origin n=111) (10 studies) |
Vitamin D deficiency (primary) Severe vitamin D deficiency Secondary hyperparathyroidism Level of 25(OH)D, nmol/L Level of s-PTH pmol/L |
Vitamin D deficiency (25(OH)D < 20 nmol/L), Arabs: 10.45 (4.63–23.58) Moderate deficiency (25(OH)D < 25 nmol/L), Pakistani: 177 (102–308) Moderate deficiency (25(OH)D < 25 nmol/L), Somali: spring 10.96 (3.44–34.95) Secondary hyperparathyroidism (s-iPTH ≥ 8.5 pmol/L + 25(OH) D < 50 + s-Ca ≤1.35 nmol/L), Pakistani: 3.86 (2.22–6.70) |
Deficiency, low level: Calcidiol (< 20 nmol/L), Pakistani: 62% (43–81%) Moderate deficiency (25(OH)D < 25 nmol/L), Pakistani: 70.8% (63.3–78.4%) Moderate deficiency (25(OH)D < 25 nmol/L), Somali: autumn 77% (46–108%), spring 66% (34–99%) 25(OH)D (< 20 nmol/L), Arabs: 86% (56–116%) Severe deficiency (< 10 nmol/L), Arabs: 85% (76–94%) Severe deficiency (25(OH)D < 12.5 nmol/L), Pakistani: 20.7% (16.6–24.5%) Secondary hyperparathyroidism (s-iPTH ≥ 8.5 pmol/L + 25(OH) D < 50 + s-Ca ≤1.35 nmol/L), Pakistani: 17.3% (10.2–24.3%) Level Calcidiol, Pakistani: –43 nmol/L Level 25(OH)D, Arabs: –40.0 nmol/L Level 25(OH)D, Pakistani: –51.9; –50.1 nmol/L Difference in PTH level, Arabs: 2.0 pmol/L s-iPTH level, Pakistani: 2.6 pmol/L; 1.9, 2.43 (age-adjusted) |
1 A 8 B 1 C |
Convincing | |
| Vitamin D deficiency in the adult general population, men |
N=1,697 (immigrants n=889, indigenous n=723, country of origin n=85) (7 studies) |
Vitamin D deficiency (primary) Severe vitamin D deficiency Secondary hyperparathyroidism Level of 25(OH)D, nmol/L Level of s-PTH pmol/L |
Secondary hyperparathyroidism (s-iPTH ≥ 8.5 pmol/L + 25(OH) D < 50 + s-Ca ≤1.35 nmol/L), Pakistani: 5.53 (2.82–10.84) | Moderate deficiency (25(OH)D < 25 nmol/L), Pakistani: 51.0% (43.7–58.2%) Severe deficiency (25(OH)D < 12.5 nmol/L), Pakistani: 8.7% (5.7–11.6%) Secondary hyperparathyroidism (s-iPTH ≥ 8.5 pmol/L + 25(OH) D < 50 + s-Ca ≤1.35 nmol/L), Pakistani: 13.4% (8.1–18.7%) Level 25(OH)D, Pakistani: –44.4; –44.7 nmol/L s-iPTH level, Pakistani: 1.2 pmol/L,; 0.8, 1.03 (age-adjusted) |
1 A 5 B 1 C |
Convincing | |
| Vitamin D deficiency in the adult general population, women and men |
N=3,976 (immigrants n=1,993, indigenous n=1,787, country of origin n=196) (10 studies) |
25(OH)D: –49.8 (–53.4–46.2) nmol/L |
1 A 8 B 1 C |
Convincing | |||
| Vitamin D deficiency in the adult general population, women, compared to country of origin |
n=209 Tamils in Norway n=89 Tamils in Sri Lanka n=111 (one study) |
Vitamin D deficiency (primary) Level of 25(OH)D, nmol/L |
Vitamin D deficiency (25(OH)D < 20 nmol/L), Tamils in Norway vs. in Sri Lanka: 5.50 (2.67–11.33) | Deficiency (25(OH)D < 25 nmol/L), Tamils in Norway vs. in Sri Lanka: 28.4% (16.4–40.4%) 25(OH)D: –17.1 (–21.0–13.2) nmol/L |
1 A | Convincing | Only one study, but of high quality with distinct results |
| Vitamin D deficiency in the adult general population, men, compared to country of origin |
n=229 Tamils in Norway n=144 Tamils in Sri Lanka n=85 (1 study) |
Vitamin D deficiency (primary) Level of 25(OH)D, nmol/L |
Deficiency (25(OH)D < 25 nmol/L), Tamils in Norway vs. in Sri Lanka: 31.9% (19.9–44.0%) 25(OH)D: –30.6 (–35.4–25.8) nmol/L |
1 A | Convincing | Only one study, but of high quality with distinct results | |
| Vitamin D deficiency in the adult general population, women and men, compared to country of origin |
n=438 Tamils in Norway n=242 Tamils in Sri Lanka n=196 (1 study) |
Vitamin D deficiency (25(OH)D < 20 nmol/L), Tamils in Norway vs. in Sri Lanka: 9.26 (4.91–17.44) | Deficiency (25(OH)D < 25 nmol/L), Tamils in Norway vs. in Sri Lanka: 29.5% (21.1–37.9%) 25(OH)D: –22.7 nmol/L |
1 A | Convincing | Only one study, but of high quality with distinct results |