- Treatment of iodine deficiency in school-age children increases insulin-like growth factor (IGF)-I and IGF binding protein-3 concentrations and improves somatic growth. Zimmermann, M.B., Jooste, P.L., Mabapa, N.S., Mbhenyane, X., Schoeman, S., Biebinger, R., Chaouki, N., Bozo, M., Grimci, L., Bridson, J. J. Clin. Endocrinol. Metab. (2007)