Aim: The aim of the study is to examine the relationship between obesity, Vitamin-D deficiency, and protein oxidation. Methods: Thiol-disulfide homeostasis, Vitamin-D, ischemia modified albumin, insulin, and lipid levels were compared among obese, pre-obese and normal-weight healthy children. Results: A total of 136 children (69 boys and 67 girls) were included in the study. The vitamin-D levels of obese children were lower than those of pre-obese and normal weight (p < 0.05). In the normal weight group, total thiol and native thiol were lower in the pubertal period than in adolescence; were higher in those with sufficient Vitamin-D level than those with insufficient and deficient Vitamin-D (p < 0.05). Vitamin-D level was lower in pre-obese girls than boys (p < 0.05). Those with high triglycerides had high disulfide/total thiol, disulfide, and disulfide/native thiol and low native thiol/total thiol (p < 0.05). Conclusion: Thiol-disulfide homeostasis is negatively affected by low vitamin D levels, pubertal period and high triglyceride levels.
Keywords: children; obese; pre-obese; thiol-disulfide homeostasis; vitamin D.