Endocrine Abstracts

Despite significant progress, deficiencies of iron and iodine remain major public health problems affecting >30% of the global population. These deficiencies often coexist in populations. Iron deficiency has adverse effects on thyroid metabolism. Iron deficiency impairs thyroid hormone synthesis by reducing activity of heme-dependent thyroid peroxidase. Iron-deficiency anemia blunts, and iron supplementation improves the efficacy of iodine supplementation. Studies have demonstrated that a high prevalence of iron deficiency among children in areas of endemic goiter may reduce the effectiveness of iodized salt programs. These findings argue strongly for improving iron status in areas of overlapping deficiency, not only to combat anemia but also to increase the efficacy of iodine prophylaxis. Poor maternal iron status predicts both higher TSH and lower TT4 concentrations during pregnancy in an area of borderline iodine deficiency.