Excessive abdominal adiposity and body fat are associated with lower serum vitamin D levels: A population-based study

ABSTRACT Objective To estimate the prevalence of 25-hydroxyvitamin D deficiency and to analyze factors associated with lower serum vitamin levels in Brazilian adults. Methods A cross-sectional, population-based study consisted of 626 adult individuals of both sexes living in the urban area of Viçosa, Minas Gerais. The dependent variable used was the serum level of 25-hydroxyvitamin D and the independent variables were sociodemographic, anthropometric and body composition variables. The associations among the variables were verified using simple and multiple linear regression models, considering alpha lower than 0.05 for the input in the final model. Results The prevalence of 25-hydroxyvitamin D deficiency was 14.4% and the prevalence was 42.0%. Excess abdominal fat was higher in subjects with 25-hydroxyvitamin D sufficiency. The serum level of 25-hydroxyvitamin D was 30.34±9.85ng/ml. Body adiposity was higher in men with vitamin insufficiency. Negative associations were observed between serum 25-hydroxyvitamin D levels and age, educational level, body adiposity (p=0.028) and abdominal adiposity (p=0.023). Conclusion Our results showed that excess body and abdominal adiposity are strong predictors of alterations in the serum vitamin D levels, thus public policies for prevention and treatment in this population are essential.

摘要
目的：评估巴西成年人25-羟维生素D（25-hydroxyvitamin D）缺乏的患病率，并分析与血清维生素D水平降低相关的影响因素。
方法：本研究为基于人群的横断面研究，共纳入626名居住于米纳斯吉拉斯州维索萨城区的成年男女受试者。本研究的因变量为血清25-羟维生素D水平，自变量涵盖社会人口学、人体测量学及身体成分相关指标。采用简单线性回归与多元线性回归模型验证变量间的关联，设定检验水准α<0.05以将变量纳入最终回归模型。
结果：25-羟维生素D缺乏的患病率为14.4%，整体患病率为42.0%。血清25-羟维生素D水平均值为30.34±9.85ng/ml。血清25-羟维生素D水平充足的受试者腹部脂肪过量的比例更高。维生素D不足的男性体脂水平更高。血清25-羟维生素D水平与年龄、受教育程度、体脂（p=0.028）及腹部脂肪量（p=0.023）呈负相关。
结论：本研究结果显示，体脂与腹部脂肪过量是血清维生素D水平异常的强预测因子，因此针对该人群制定维生素D防治的公共卫生政策至关重要。