Effects of Iodine Supplementation on Physical and Psychomotor Development in Young Children and their Neurological Status

Iodine is an essential element for the synthesis of thyroid hormones. Thyroid function is crucial to the metabolism of almost all tissues and is critical for the development of the central nervous system in the fetus and children.

Objective: To evaluate effects of iodine supplementation on physical and psychomotor development in young children and their neurological status.

Materials and Methods: Target group: 118 children 0-3 years old from orphanage. Methods: physical and psychomotor development accession; dietary iodine intake evaluation by urinary iodine concentration (Sandell-Kolthoff reaction); thyroid status by TSH, TT4, TT3 serum-based measuring (IMA)_. Iodine intake: infant formula (iodine concentration 100 µg/l) and additional iodine supplementation in 51 children by drugs (50 µg per day for 6 months).

Results: All children were accepted into an orphanage at the age 2,5-3,5 months. They had burdened prenatal history (100%), decreased physical development (44.9%), deficiency in psychomotor development (95.7%), decreased coefficient of neuropsychological development (82 points) and neurological signs (94.1%). The most common was the signs of static, kinetic, mental and pre-speech retardation (49.2%, p˂0.001). Median urinary iodine excretion was 56.5 µg per day. Median TSH level was 3.21 mU/l [QR: 3.1; 3.8]. Negative linear correlation by PPMCC between TSH levels and coefficients of neuropsychological development was detected (ρ=-0.436, p<0.001). Iodine supplementation per 6 months reduced median TSH level up to 1.96 mU/l [QR: 1,77; 2,01] (p˂0.001) vs median TSH level in control group 2,99 mU/l [QR: 2,43; 3,98], p˂0.001. That resulted in improvement of anthropometry indicators (92.3 %, p˂0.001) and psychomotor development (50 %, p˂0.001). The coefficient of neuropsychological development increased (up to 92 points). The frequency of neurological signs reduced (28.9 %, p˂0.001).

Conclusions: Iodine supplementation in young children with developmental retardation improves their growth, cognitive, emotional, motor, and social capacities, reduces neurological dysfunction rate.