Associations of Physical Activity and Sitting Time with Serum Vitamin D Status in Korean Adults: Results from the 2014 Korea National Health and Nutrition Examination Survey

ABSTRACT

Background@#Recent evidence has reported the relationships between 25-hydroxyvitamin D (25[OH]D) insufficiency and chronic diseases. This study examined the association of physical activity and sitting time with vitamin D status. @*Methods@#This study analyzed the data of 1,598 adults aged ≥19 who participated in the 2014 Korea National Health and Nutrition Examination Survey. Vitamin D insufficiency was defined as a serum 25(OH)D level of ≤20 ng/mL. The odds ratios and 95% confidence intervals of vitamin D insufficiency according to physical activity and sitting time were calculated using a multivariable logistic regression analysis. @*Results@#The mean levels of serum 25(OH)D were 16.5 ng/mL in males and 15.2 ng/mL in females, respectively and was significantly higher in the participants with sitting times of <5 hours/day than those with sitting times of ≥5 hours/day. After adjusting for confounding variables, sitting time of <5 hours/day was associated with decreased odds of vitamin D insufficiency as compared with sitting time of ≥5 hours/day in the total participants and females. In addition, the odds ratio for vitamin D insufficiency was significantly lower in the group with sitting times of <5 hours/ day than in the group with sitting times of ≥5 hours/day even among people with low physical activity in the total participants and females. @*Conclusion@#Serum 25(OH)D level was insufficient in the Korean adults and shorter sitting time was related to lower odds ratio of vitamin D insufficiency. Our findings suggest that sitting time is an independent factor of serum vitamin D status.