Effect of country of origin, age, and body mass index on prevalence of vitamin D deficiency in a US immigrant and refugee population.

OBJECTIVE

To determine the prevalence of vitamin D deficiency (VDD) (25-hydroxyvitamin D level <20 ng/mL) and severe VDD (25[OH]D level <10 ng/mL) in a Minnesota immigrant and refugee population.

PATIENTS AND METHODS

This retrospective study evaluated a cohort of adult immigrants and refugees seen at Health Partners Center for International Health in St Paul, Minnesota. Study participants were all patients seen from August 1, 2008, through July 31, 2009, with a first vitamin D screen (N=1378). Outcomes included overall prevalence of VDD and severe VDD. Covariates included country of origin, sex, age, month of test, and body mass index (BMI).

RESULTS

Vitamin D deficiency was significantly more prevalent in our Minnesota clinic immigrant and refugee population than among US-born patients (827 of 1378 [60.0%] vs 53 of 151 [35.1%]; P<.001). Severe VDD was also significantly more prevalent (208 of 1378 [15.1%] vs 12 of 151 [7.9%]; P=.02). Prevalence of VDD varied significantly according to country of origin (42 of 128 Russian patients [32.8%] vs 126 of 155 Ethiopian patients [81.3%]; P<.001). The BMI correlated [corrected] with VDD (488 of 781 [62.5%] when BMI was ≥ 25 vs 292 of 520 [56.2%] when BMI was <25; P=.02). Vitamin D deficiency was present in 154 of 220 individuals (70.0%) 16 to 29 years old vs 123 of 290 (42.4%) in those older than 66 years (P<.001).

CONCLUSION

Immigrants and refugees in a Minnesota clinic have a substantially higher rate and severity of VDD when compared with a US-born population. Country of origin, age, and BMI are specific risk factors for VDD and should influence individualized screening practices.