title: Vitamin D status and associated occupational factors in Korean wage workers: data from the 5th Korea national health and nutrition examination survey (KNHANES 2010-2012).
abstract: OBJECTIVE
  Vitamin D deficiency is increasing worldwide. However, few studies have attempted to examine the vitamin D status of wage workers and the correlation between vitamin D deficiency and working conditions. Hence, we aimed to evaluate the prevalence of vitamin D deficiency and the association between occupational conditions and vitamin D deficiency among Korean wage workers.
  
  
  METHODS
  Wage workers aged 20-65 years from the 5th Korea National Health and Nutrition Examination Survey (KNHANES 2010-2012; n = 5409) were included in our analysis. We measured the prevalence of vitamin D deficiency and identified the correlations with the working conditions of these subjects.
  
  
  RESULTS
  The prevalence of vitamin D deficiency in male and female subjects was 69.5% and 83.1%, respectively. Among the male subjects, a significant correlation between vitamin D deficiency and working conditions was observed among shift workers, office workers, and permanent workers. No significant correlation with any type of working conditions was observed among female subjects.
  
  
  CONCLUSIONS
  The prevalence of vitamin D deficiency among Korean wage workers was very high and was found to correlate significantly with working conditions, likely because of insufficient exposure to sunlight associated with certain types of work. Wage workers require more frequent outdoor activity and nutrition management to maintain sufficient vitamin D level.
authors: Department of Occupational Medicine, Korea University Hosipital, 123, Jeokgeum-ro, Ansan, Gyeonggido, Republic of Korea.
authors: Harin
authors: H
authors: Jeong
authors: Department of Occupational Medicine, Korea University Hosipital, 123, Jeokgeum-ro, Ansan, Gyeonggido, Republic of Korea.
authors: Sujin
authors: S
authors: Hong
authors: Department of Occupational Medicine, Korea University Hosipital, 123, Jeokgeum-ro, Ansan, Gyeonggido, Republic of Korea.
authors: Yunjeong
authors: Y
authors: Heo
authors: Department of Occupational Medicine, Korea University Hosipital, 123, Jeokgeum-ro, Ansan, Gyeonggido, Republic of Korea.
authors: Hosun
authors: H
authors: Chun
authors: Department of Occupational Medicine, Korea University Hosipital, 123, Jeokgeum-ro, Ansan, Gyeonggido, Republic of Korea.
authors: Daeseong
authors: D
authors: Kim
authors: Department of Occupational Medicine, Korea University Hosipital, 123, Jeokgeum-ro, Ansan, Gyeonggido, Republic of Korea.
authors: Jongtae
authors: J
authors: Park
authors: Department of Occupational Medicine, Wonjin green hospital, 49-53, Sagajeong-ro, Jungnang-gu, Seoul, Republic of Korea.
authors: Mo-Yeol
authors: MY
authors: Kang
keywords: Indoor work; KNHANES; Office work; Shift work; Vitamin D deficiency