Iodine deficiency is an important public health problem worldwide. In addition to severe consequences such as brain damage, developmental delay, deficits in hearing and learning, it also has a negative impact on growth. The negative impact of severe
iodine deficiency (
SID) on
insulin-like growth factor-I (
IGF-I) and
insulin-like growth factor binding protein-3 (IGFBP-3) was shown previously. In this study we aimed to analyze the impact of
iodine supplementation on growth and
growth factors of children with
SID. One hundred and four children (63 boys and 41 girls) aged 5-15 years participated in the study. Height standard deviation scores (HSDS), and serum levels of
IGF-I and
IGFBP-3 were assessed both before and six months after a single dose of
iodized oil. Serum levels of free
thyroxine (FT4) and
thyroid stimulating hormone (TSH) were also analysed to investigate the mechanisms by which alterations of
iodine status may influence growth. Pubertal children had lower HSDS six months after
iodine supplementation, while that of prepubertal children remained unchanged.
IGF-I and
IGFBP-3 levels decreased significantly and FT4 levels were suppressed six months after the supplementation, while TSH was normalized. These findings suggest a negative impact of
iodine supplementation on
growth factors in the short-term, which may be a direct effect of
iodine repletion or an indirect effect caused by alterations in thyroid function. It may also be related to the method of supplementation used. Further studies are necessary to resolve these issues, as well as to examine the impact of
iodine supplementation on growth in the long-term.