Major Finding: The odds of being obese were 0.42 lower among children with serum vitamin C levels of 76.1-195 micromol/L, compared with children who had serum vitamin C levels of 9-76 micromol/L.
Data Source: A study of 1,133 healthy weight or obese children aged 6-11 years who were included in the NHANES data sets from 2003-2004 and 2005-2006.
Disclosures: Ms. Ewing had no relevant financial conflicts.
SAN DIEGO — Low serum levels of vitamin C are associated with obesity in children aged 6-11 years, results from an analysis of data from the National Health and Nutrition Examination Survey showed.
“Childhood nutrition and obesity are significant public health concerns that may result in abnormal growth and development,” researchers led by Kelly Ewing wrote in a poster presented at the meeting “Although numerous studies have characterized vitamin C intake and serum levels, and have demonstrated an inverse association with obesity in adults, as far as we are aware, no studies to date have looked at this relationship in a pediatric population.”
She and her associates performed a cross-sectional, retrospective study of 1,133 healthy weight or obese children aged 6-11 years who were included in the NHANES data sets from 2003-2004 and 2005-2006, for whom relevant medical, socioeconomic, physical activity, anthropometric, and serum vitamin C data were complete.
The researchers divided the children into two groups based on their serum vitamin C concentrations: a lower 50% group (defined as having a vitamin C level of 9-76 micromol/L), and an upper 50% group (vitamin C level of 76.1-195 micromol/L).
Of the 1,133 children, 876 (77%) had a healthy weight and 257 (23%) were obese, said Ms. Ewing, who worked on the study while completing her master's degree in the department of clinical research at the Campbell University College of Pharmacy and Health Sciences, Buies Creek, N.C.
The researchers then conducted a bivariate analysis to identify significant associations between weight status and vitamin C concentration, race, sex, physical activity, and socioeconomic status. They found that that the odds of being obese were 0.42 lower in the upper 50% vitamin C level group, compared with the lower 50% group, when socioeconomic status was also considered.
Hours of physical activity and sex were not significant factors in the link between serum vitamin C levels and obesity, but race and income were. A higher proportion of nonwhite children were obese, compared with white children (26% vs. 16%, respectively), and a higher proportion of obese children were from households with an income of $24,999 or less per year (29% vs. 20%).
“I was surprised that socioeconomic status didn't kill the relationship,” Ms. Ewing said in an interview. “I figured that would have a bigger effect than just the vitamin C itself, because it's very established in the medical literature that obesity and economic status are inversely related.”
She acknowledged certain limitations of the study, including the fact that there was no way to know if serum was drawn while the children were fasting. “Our biggest limitation is that we were not sure what the kids were eating,” she added. “There was a food frequency questionnaire that we looked at. However, it was a yearlong recall that did not account for serving size.”