The relationship between body fat mass and vitamin D appears to vary by ethnicity, but our understanding of this predisposition in Asians is limited due to the scarcity of prior investigations. Data on 1,697 Korean adults were obtained from the second and third years (2008-2009) of the fourth Korean National Health and Nutritional Examination Survey. Body fat mass was measured using dual-energy X-ray absorptiometry. Both linear regression analysis for serum 25-hydroxyvitamin D [25(OH)D] and logistic analysis for vitamin D deficiency [25(OH)D <20 ng/mL] were performed to determine significant predictors among BMI, waist circumference (WC), and body fat percentage (BF), after adjustment of multiple covariates. To explore a possible non-linear relationship between them, the fractional polynomials method was used. All analyses were conducted following stratification by sex. In linear regression analysis, BMI and WC were not associated with 25(OH)D. However, BF was inversely related to 25(OH)D, irrespective of the fat location (both appendicular and truncal fat) in both sexes. In logistic regression analysis, the highest quartile group of BF had a greater OR for vitamin D deficiency than the lower quartile groups, irrespective of the fat location and sex. However, the quartiles of BMI and WC were not associated with vitamin D deficiency. The linear relationships between BF and 25(OH)D (or vitamin D deficiency) were confirmed despite use of the fractional polynomials method. Body fat mass is inversely associated with serum 25(OH)D in Korean adults. Monitoring of vitamin D deficiency in Korean adults with high fat mass is needed.
體脂肪與維生素D 的相關性受到種族的影響，但由於先前研究的缺乏，這個 論點在亞洲人仍未確認。來自於第四次韓國國家健康與營養調查的第二及第三 年(2008-2009)的1697 名韓國成人資料納入本研究。體脂肪量是以雙能量X 光 吸收儀測量的。以直線迴歸分析血清25-羥維生素 D[25(OH)D]，及以邏輯斯迴 歸分析維生素D 缺乏[25(OH)D<20 ng/mL]，以評估校正多種共變項後， BMI、腰圍或體脂肪是否為顯著預測因子。以分數多項式法探究它們之間可能 的非線性關係。所有的分析以性別分層。線性迴歸分析結果，BMI 及腰圍與 25(OH)D 沒有相關性。然而，男女性的體脂肪與25(OH)D 為負相關，並與脂 肪部位(四肢及軀幹脂肪)無關。由邏輯斯迴歸分析結果指出，最高四分位的體 脂肪組比起最低四分位組，有較高的維生素D 缺乏風險，與脂肪部位及性別 無關。然而，BMI 及腰圍的四分位與維生素D 缺乏沒有相關性。即使用分數 多項式法分析，體脂肪與25(OH)D(或是維生素D 缺乏)間的直線相關仍然存 在。韓國成人的體脂肪量與血清25(OH)D 呈現負相關。因此有必要監測高體 脂肪量的韓國成人之維生素D 缺乏。