Effects of increased iodine supply on the selenium status of kids

Abstract

The aim of the study was to monitor the effect of increased iodine supplementation of the clinically healthy kid organism on the selenium status. The study included 7 clinically healthy 14-day-old kids from mothers with high iodine supplementation (group E) and 7 clinically healthy kids from mothers with hypoiodaemia (group C). Kids in group E were administered potassium iodide orally from 14 to 90 days of age. During the experimental period, the group E kids had a total daily iodine intake (from the feeding ration and from the per os potassium iodide administration) of 440–590 µg per head and day in comparison with 140–190 µg per head and day in the group C kids (only from the feeding ration; no potassium iodide administration). In kids of both groups, selenium concentration (Se), glutathione peroxidase activity (GSH-Px), concentration of the thyroid gland hormones (T₃ and T₄) and animal weights were monitored. In the group E kids, lower Se concentration (88.1 ± 10.9 µg/l; p < 0.01) and lower activity of GSH-Px (484.0 ± 125.4 µkat/l; p < 0.05) were proved at the end of the experiment (at 105 days of age of the kids) in comparison with the group C kids (131.8 ± 23.2 µg/l and 713.3 ± 153.3 µkat/l, respectively). No significant differences were found out in the T₃ or T₄ concentrations or in the weights of animals of both groups. The results indicate that increased iodine supplementation may have a negative effect on selenium metabolism and/or selenium status in kids.