Population groups in dietary transition

Figures & data

Table 1 Population in the Nordic countries 2010, with regard to countries of origin

	Denmark	Faroe islands	Finland (including Åland)	Iceland	Norway	Sweden
Population	5,534,738	48,568	5,379,161	317,630	4,858,199	9,340,682
All foreign-born (% of all)	501,511 (9.96%)	5,912 (12.17%)	236,766 (4.60%)	35,121 (11.06%)	526,799 (10.84%)	1,337,965 (14.32%)
Nordic countries	76,286 (15.21%)	3,793 (64.16%)	35,543 (15.01%)	6,314 (17.98%)	76,974 (14.61%)	266,519 (19.92%)
Europe (except Nordic c.)	180,532 (36.00%)	492 (8.32%)	114,852 (48.51%)	20,361 (57.97%)	189,672 (36.00%)	441,954 (33.03%)
America	27,909 (5.56%)	147 (2.49%)	9,946 (4.20%)	2,877 (8.19%)	41,650 (7.91%)	92,610 (6.92%)
Africa	35,377 (7.05%)	101 (1.71%)	20,489 (8.65%)	780 (2.22%)	53,579 (10.17%)	103,077 (7.70%)
Western Asia	79,587 (15.87%)	6 (0.10%)	15,992 (6.75%)	193 (0.55%)	47,273 (8.97%)	261,954 (19.58%)
South Asia	27,288 (5.44%)	60 (1.01%)	6,659 (2.81%)	460 (1.31%)	34,932 (6.63%)	37,769 (2.82%)
Southeast Asia	28,705 (5.72%)	133 (2.25%)	12,231 (5.17%)	2,949 (8.40%)	39,505 (7.50%)	48,589 (3.63%)
East Asia	12,012 (2.40%)	18 (0.30%)	7,701 (3.25%)	569 (1.62%)	10,055 (1.91%)	24,096 (1.80%)
Rest of Asia	29,609 (5.90%)	69 (1.17%)	7,389 (3.12%)	454 (1.29%)	30,751 (5.84%)	56,395 (4.21%)
Oceania	3,259 (0.70%)	13 (0.22%)	1,119 (0.47%)	138 (0.39%)	2,408 (0.46%)	4,251 (0.32%)
Unknown/stateless	947 (0.19%)	1,080 (18.27%)	4,845 (2.05%)	26 (0.07%)	0 (0.00%)	751 (0.06%)

Figure 1 Flowchart for study of articles regarding population groups in dietary transition.

Table 2 Vitamin D deficiency among immigrant children 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	Comments
Vitamin D deficiency among children 0–16 years of age	309 (immigrants 191, controls 118) (3 studies)	Vitamin D deficiency (primary) Secondary hyperparathyroidism		Vitamin D deficiency (25(OH)D < 25 nmol/L): All 60% (46–74%) Secondary hyperparathyroidism (s-PTH > 7.6 pmol/L): All 26% (17–36%)	3 B	Convincing	Lack of comparative data with indigenous population, but high rate of deficiency
Vitamin D deficiency among children 0–8 years of age	152 (immigrants 127, indigenous 25) (2 studies)	Vitamin D deficiency (primary) Secondary hyperparathyroidism Level of 25(OH)D, nmol/L		Vitamin D deficiency (25(OH)D < 25 nmol/L): All 46% (20–73%) Secondary hyperparathyroidism (s-PTH > 7.6 pmol/L): All 16% (–0.4 –30%) Level of 25(OH)D2 + 3: –13.7 nmol/L	2 B	Convincing	Lack of comparative data with indigenous population, but high rate of deficiency
Vitamin D deficiency among children 9–16 years of age	157 (immigrants 64, indigenous 93) (2 studies)	Vitamin D deficiency (primary) Secondary hyperparathyroidism Level of 25(OH)D, nmol/L		Deficiency (25(OH)D < 25 nmol/L): All 81% (63–100%) Secondary hyperparathyroidism (s–PTH >7.6 pmol/L): All 44% (31–58%) Boys 17% (4–29%) Girls 67% (43–91%) Level of 25(OH)D: Boys –13.7 nmol/L Girls –20.2 nmol/L	2 B	Convincing	Lack of comparative data with indigenous population, but high rate of deficiency
Nutritional rickets among children aged 0–16 years	198 (immigrants 167, indigenous 31) (3 studies)	Incidence of nutritional rickets		All immigrants born I Denmark 0.60 (0.39–0.81) ‰ per year Middle East immigrants born in Denmark 0.84 (0.48–1.23) ‰ per year	1A 1B 1C	Convincing
Nutritional rickets among children aged 0–4 years	95 (immigrants 66, indigenous 29) (2 studies)	Incidence of nutritional rickets	49 (31–77)	All immigrants born in Denmark 0.97 (0.86–1.08) ‰ per year	1 A 1 B	Convincing

Table 3 Vitamin D deficiency among immigrant pregnant women 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 orC	Strength of evidence (convincing, probable, limited-suggestive, limited-no conclusion)	Comments
Vitamin D deficiency pregnant women	N=227 Immigrant women n=227 Ethnic Norwegians n=61 (4 studies)	Vitamin D deficiency Severe vitamin D deficiency Vitamin D level Secondary hyperparathyroidism PTH level	Subnormal level (Calcidiol < 30 nmol/L): 2.78 (1.31–5.88) Low level (Calcidiol <20 nmolL): 6.90 (1.96–24.23) (25(OH)D3<30 nmol/L): 15.00 (5.13–43.83)	Difference in subnormal level (Calcidiol < 30 nmol/L): 62% (42–82%) Low level (Calcidiol <20 nmolL): 51% (30–72%) (25(OH)D3<30 nmol/L): 77% (62–92%) Difference in rate of secondary hyperparathyroidism (PTH > 5.5 pmol/L): 43% (25–61%) Difference in vitamin D level: S–25(OH)D3 –36 nmol/L (median) Difference in PTH level: 1 pmol/L (median)	4 B	Convincing

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 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		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

Table 5 Iron deficiency among immigrants in the Nordic countries

Exposure/intervention	No. of participants (No. of studies)	Outcome variable (primary or secondary)	RR (95% CI)	Effect (95% CI)	Nuo. of studies rated as A B C	Strength of evidence (convincing, probable, limited-suggestive, limited-no conclusion)	Comments
Iron deficiency, children	n=74 (immigrants n=39) (1 study)	Anemia (primary) Sideropen anemia: Hb < 11 g/100 ml+ s-Ferritin <15 µg/L Empty iron deposits (ferritin < 10 µg/L) Severely low iron deposits (ferritin < 15 µg/L)	Anemia (Hb < 11 g/100 ml): 2.03 (0.54–7.65) Severely low iron deposits (ferritin < 15 µg/L): 2.14 (0.77–5.93)	Anemia (Hb < 11 g/100 ml): 9.1% (–7.9–26.1%) Sideropen anemia (Hb < 11 g/100 ml+ s-Ferritin <15 µg/L): 10.8% (–0.4–22.0%) Empty iron deposits (ferritin < 10 µg/L): 13.5% (1.0–26.1%) Severely low iron deposits (ferritin < 15 µg/L): 17.3% (–5.8 –40.4%)	1 B	Limited – suggestive
Iron deficiency, pregnant women	n=76 (Pakistani women n=38) (1 study)	Anemia (primary) Low iron deposits (low ferritin) Microcytosis (low MCV)	Anemia (Hb < 11 g/100 ml): 1.63 (0.68–3.89) Low iron deposits (ferritin <12 µg/L): 4.33 (1.92–9.77) Microcytosis (MCV <82): 6.75 (2.73–16.70)	Anemia (Hb < 11 g/100 ml): 13.2% (–10.5–36.8%) Low iron deposits (ferritin <12 µg/L): 52.6% (23.5–81.8%) Microcytosis (MCV <82): 60.5% (31.8–89.2%)	1 B	Probable

Table 6 Caries among immigrant children in the Nordic countries

Exposure/intervention	No. of participants (No. of studies)	Outcome variable (primary or secondary)	RR (95% CI)	Effect	No. of studies rated as A B C	Strength of evidence (convincing, probable, limited-suggestive, limited-no conclusion)	Comments
Preschool children (< 7 years of age)	n=2,571 (immigrants 1,273, indigenous 1,298) (6 studies)	Manifest caries (primary) Dmf score	2.5 years: RR 2.46 (1.34–4.51) Adjusted OR 4.10 (2.06–6.14) From 1 to 2.5 years: Adjusted OR 2.34 (1.33–4.13) 3. 5 years: RR 3.13 (2.26–4.33) From 2.5 to 3.5 years: Adjusted OR 2.25 (1.36–3.73) 4 years, 2006: RR 1.83 (1.11–3.02)	2.5 years: 5.1% (1.7–8.6%) 3.5 years: 28.7% (20.5–36.8%) 4 years, 2006: 27% (5–49%) 4 years, dmfs: 1997: 2.2 (–0.6–5.0) 2002: 5.3 (2.3–8.3) 2006: 3.1 (1.1–5.0)	1 A 5 B	Convincing
Early school age (7 years of age)	n=192 (immigrants 152, indigenous 40) (1 study)	Manifest caries Dmf score	dmfs + DMFS (mean caries experience with significance level according to Student's t-test): Turkish: RR 2.4** Pakistani: RR 1.9* Albanian: RR 4.1 *** Somali: RR 0.7 Arabian: 3.2*** PP (prevalence proportion rate): All immigrants: RR 1.48 (0.93–2.35) OR 3.14 (1.53–6.47)	PP (prevalence proportion rate): Turkish: 32% (–4 – 69) Pakistani: 21% (–14 – 56) Albanian: 32% (–9 – 72) Somali: 9% (–33 – 50) Arabian: 26% (–12 – 63) All immigrants: 25% (–5 – 55)	1 B	Probable
Teenagers (15 years of age)	n=278 (immigrants 170, indigenous 108) (2 studies)	Manifest caries DMF score	DMFS (mean caries experience): Turkish: RR 1.9 Pakistani: RR 1.0 Albanian: RR 2.7*** Somali: RR 0.5 Arabian: RR 1.5 (differences according to Student's t-test) PP (prevalence proportion rate): All immigrants: RR 0.79 (0.65–0.96) OR 0.42 (0.18–0.96)	PP (prevalence proportion rate): Turkish: –4% (–22 – 14) Pakistani: –24% (–46–3) Albanian: 7% (–12 – 27) Somali: –48% (–81 – 15) Arabian: –2% (–22 – 18) All immigrants: –17% (–32–2)	2 B	Limited – no conclusion

* denotes p < 0.05, ** p < 0.01 and *** p < 0.001.