Prevalence of vitamin D deficiency and its association with nutrition, travelling and clothing habits in an immigrant population in Northern Sweden

OBJECTIVES: To study prevalence and determinants of vitamin D deficiency in immigrants from Africa and the Middle East living in Umea, Sweden. DESIGN: Cross-sectional population based. SETTING: Umea, Sweden (63 degrees N). SUBJECTS/METHODS: Immigrants aged 25-65 years from nine countries in Africa or the Middle East (n = 1306) were invited. A total of 111 men and 106 women (16.5%) completed the study. S-25-hydroxyvitamin D3 was measured with HPLC. Anthropometry, medical, socioeconomic and lifestyle data were registered. RESULTS: Vitamin D status was insufficient or deficient in 73% of the participants. Specifically, 12% had vitamin D deficiency (25 (OH) D3 < 25 nmol/l), and only 3.7% had optimal vitamin D status (25(OH) D3 75-125 nmol/l). Mean 25(OH) D3 level was 41.0 nmol/l (+/- 16.6) with no difference between sexes. Levels of 25(OH) D3 were lower (P = 0.030) and vitamin D deficiency was twice as common in immigrants from Africa compared with those from the Middle East. In the multiple regression analysis, vitamin D deficiency was significantly associated with low fatty fish intake (OR 4.31, 95% CI 1.61-11.55), not travelling abroad (OR 3.76, 95% CI 1.18-11.96) and wearing long-sleeved clothes in summer (OR 3.15, 95% CI 1.09-9.12). CONCLUSIONS: The majority of immigrants from Africa and the Middle East who live in northern Sweden have vitamin D deficiency or insufficiency. Our results are consistent with sun exposure and a diet with high intake of fatty fish being most important in avoiding vitamin D deficiency.