Vitamin D status and associated metabolic risk factors among North Korean refugees in South Korea: a cross-sectional study

BMJ Open. 2015 Nov 30;5(11):e009140. doi: 10.1136/bmjopen-2015-009140.

Abstract

Objective: Vitamin D deficiency is now recognised as a common health problem associated with various chronic diseases; however, it has not been fully elucidated among the minority groups. Here, we aimed to investigate the prevalence of vitamin D deficiency and its associated metabolic risk factors among North Korean refugees living in South Korea.

Design: Cross-sectional analysis from the longitudinal cohort, the North Korean refugee health in South Korea (NORNS) study.

Participants: A total of 386 North Korean refugees aged ≥30 years, who measured serum 25-hydroxy vitamin D (25(OH)D) level.

Results: The prevalence of vitamin D deficiency (25(OH)D <20 ng/mL) was 87% and no participants had an adequate vitamin D level (25(OH)D ≥30 ng/mL). Underweight participants (body mass index (BMI) <18 kg/m(2)) had significantly lower 25(OH)D levels than individuals with normal BMI (≥18.5 and<23 kg/m(2)). In the multivariate logistic regression analysis, the lowest 25(OH)D level (<10 ng/mL) was significantly associated with metabolic syndrome (OR, 6.37, 95% CI 1.34 to 30.3), high triglyceride (OR, 6.71, 95% CI 1.75 to 25.7), and low high-density lipoprotein (OR, 5.98, 95% CI 1.54 to 23.2) compared with 25(OH)D levels ≥20 ng/mL after adjusting for age, sex, season, length of residence in South Korea, physical activity and BMI.

Conclusions: Vitamin D deficiency is very common among North Korean refugees in South Korea. Despite their lower BMI, vitamin D deficiency was associated with metabolic syndrome in this population.

Keywords: Metabolic syndrome; North Korean refugees; Obesity; Vitamin D deficiency; vitamin D.

MeSH terms

  • Adult
  • Asian Continental Ancestry Group
  • Body Mass Index
  • Cross-Sectional Studies
  • Democratic People's Republic of Korea / ethnology
  • Female
  • Humans
  • Logistic Models
  • Longitudinal Studies
  • Male
  • Metabolic Syndrome / epidemiology*
  • Middle Aged
  • Multivariate Analysis
  • Nutrition Surveys
  • Refugees / statistics & numerical data*
  • Republic of Korea / epidemiology
  • Risk Factors
  • Triglycerides / blood*
  • Vitamin D / analogs & derivatives*
  • Vitamin D / blood
  • Vitamin D Deficiency / epidemiology*

Substances

  • Triglycerides
  • Vitamin D
  • 25-hydroxyvitamin D