Plasma vitamin C is inversely related to body mass index and waist circumference but not to plasma adiponectin in nonsmoking adults.

J Nutr. 2007 Jul;137(7):1757-62.

Plasma vitamin C is inversely related to body mass index and waist circumference but not to plasma adiponectin in nonsmoking adults.
Johnston CS, Beezhold BL, Mostow B, Swan PD.

Department of Nutrition, Arizona State University, Mesa, AZ 85212, USA. carol.johnston@asu.edu

Abstract
We examined the relationships between plasma vitamin C, adiposity, and the collagen-like adipokine, adiponectin. Of 118 sedentary, nonsmoking adults participating in the cross-sectional trial (35 men and 83 women aged 38.7 +/- 1.0 y with BMI of 30.4 +/- 0.6 kg/m2, plasma vitamin C concentrations of 43.5 +/- 1.3 micromol/L, and plasma adiponectin concentrations of 8.9 +/- 0.3 mg/L), 54% were obese and 24% were overweight. Plasma vitamin C was inversely related to BMI, percentage of body fat, and waist circumference in both women and men (r = -0.383 to -0.497, P < 0.025). In women but not men, these associations remained significant after controlling for body mass. Plasma vitamin C was directly related to plasma adiponectin in the women after controlling for age and vitamin C supplement use (r = 0.222, P = 0.049) but not after controlling for body mass. Twenty obese men and women participated in an intervention trial and consumed an energy-restricted diet low in vitamin C (approximately 38 mg/d) for 8 wk. Subjects were stratified by age, gender, and BMI and randomly assigned to receive placebo or vitamin C (500 mg) capsules daily. At baseline, plasma adiponectin was directly related to plasma vitamin C (r = 0.609, P = 0.021) and inversely related to body mass (r = -0.785, P = 0.001). Body mass decreased significantly during the 8 wk study in both the vitamin C (n = 6, -5.9 +/- 0.9 kg) and placebo groups (n = 8, -6.5 +/- 0.7 kg). Plasma adiponectin increased 13% from baseline by wk 8 in both groups (P < 0.05). In summary, plasma vitamin C was inversely related to markers of adiposity, particularly in women, but vitamin C supplementation did not influence the circulating concentration of adiponectin.