Vitamin D intake and bone mineral density in Korean adults: analysis of the 2009-2011 Korea National Health and Nutrition Examination Survey

BACKGROUND/OBJECTIVES: The prevalence of vitamin D deficiency in Koreans is quite high; however, until recently, Korean National Health and Nutrition Survey (KNHANES) had not analyzed the vitamin D intake among Koreans. Additionally, the Korean Dietary Reference Intake for vitamin D was established based on insufficient evidence. Therefore, we investigated vitamin D intake and its relationship with bone mineral density (BMD) in Korean adults using the combined data from the 2009-2011 KNHANES.MATERIALS AND METHODS: This study was conducted in 11,949 healthy adults. Vitamin D intake was assessed using a 24-h recall method, and the BMD was measured using dual -energy X-ray absorptiometry.RESULTS: The prevalence of vitamin D deficiency (< 20 ng/mL) was 64% in men and 77% in women. In women aged >= 50 yrs and men aged < 50 yrs, there was a significant positive correlation between vitamin D intake and serum 25-hydroxyvitamin D level after sun exposure adjustment. The BMD of postmenopausal women aged >= 50 yrs with a vitamin D intake of 5 jig/day or more was significantly higher than that of women with intake less than 5 jig/day. After adjusting for age, energy, and calcium intake, the vitamin D intake of the osteoporotic group was significantly lower than that of the osteopenia group in women.CONCLUSIONS: Since the relationship between vitamin D intake and BMD was observed in women aged >= 50 yrs, further research is needed to clarify these findings using cohort or randomized controlled trials.