Body composition in nonobese individuals according to vitamin D level.

Abstract

Obesity is associated with lower 25-hydroxyvitamin D (25OHD) levels, but the association between 25OHD deficiency and specific body composition (BC) patterns remains unclear. The aim of this study was to analyze the correlation between 25OHD levels and BC in a population of healthy, nonobese individuals. Cross-sectional, observational study including a convenience sample of community-dwelling healthy individuals aged ≥18 years who responded to a study advertisement and were randomly selected. The participants filled out a questionnaire and had fasting blood drawn and anthropometric indices taken. Dual-energy x-ray absorptiometry was performed for BC analysis (fat and lean body mass). The subjects were divided according to 25OHD levels into three groups: I (≤20 ng/mL, vitamin D deficient), II (>20 and <30 ng/mL, vitamin D insufficient), and III (≥30 ng/mL, vitamin D sufficient). Of 299 individuals selected, 51 were excluded, yielding a final sample of 248 (128 women) who had serum 25OHD levels measured. Women presented higher 25OHD levels than men (27.8±12.0 ng/mL and 24.8±11.3 ng/mL, respectively; p = 0.03). Including both sexes, Group I had greater body mass index (BMI; 26.6±2.5 kg/m2) and waist circumference (WC; 91.8.8±9.1 cm) compared with the other groups. Group I also had 75.7% and 65.3% of abnormal BMI and WC values, respectively, (p<0.05 for both) and a higher percentage of trunk and android fat confirmed by multivariate analysis. No differences in BC were observed in individuals with insufficient versus sufficient 25OHD levels. Individuals with lower 25OHD levels had increased fat in the android region and trunk. This study confirms the association of lower 25OHD levels with greater BMI and WC and increased deposition of fat in body compartments, which, even in nonobese individuals, are commonly associated with increased metabolic risk.