Thiol disulphide balance in children with vitamin B12 deficiency

Introduction and Objective: Vitamin B12 is a water-soluble vitamin that cannot be synthesized in the human body and must be taken externally with mainly animal foods. Oxidative stress develops in vitamin B12 deficiency through different mechanisms. Thiols are organic compounds containing sulfhydryl (-SH) groups formed by bonding sulfur (S) and hydrogen (H) atoms to the carbon atom. These molecules are highly sensitive to oxidative stress and are considered one of the most important antioxidants in the human body. In this study, it was aimed to investigate the thiol/disulphide balance as a marker of oxidative stress in children with vitamin B12 deficiency. Materials and Methods: 61 pediatric patients with vitamin B12 deficiency and 62 healthy children as a control group were included in the study. Vitamin B12, homocysteine, complete blood count and thiol/disulphide balance parameters of the participants were measured. The relationship between thiol/disulphide balance parameters and vitamin B12 and homocysteine was investigated. Results: The groups were similar in terms of age and gender distribution. Median vitamin B12 level was 179 (98-199) ng/L in the patient group and 298 (201-965) ng/L in the control group. Median homocysteine level was 11.2 (0.08-64.3) μmol/L in the patient group and 12 (4.5-26.6) μmol/L in the control group. Median values of homocysteine levels were within the normal range in both groups. Between the patient and control groups; no significant difference was found in terms of homocysteine, native thiol, total thiol, disulphide, disulphide/native thiol ratio, disulphide/total thiol ratio and native thiol/total thiol ratio. There was no significant correlation between thiol/disulphide balance parameters and vitamin B12 and homocysteine levels in the patient and control groups. Conclusion: It was thought that there was no serious increase in homocysteine level, since the vitamin B12 level was not significantly low in our patient group. It can be predicted that a vitamin B12 deficiency that does not increase homocysteine will not increase oxidative stress and therefore will not increase antioxidant capacity. Keywords: Homocysteine, Oxidative stress, Thiol/disulphide balance, Vitamin B12.