Millet has an interesting characteristic in that the hulls and seeds contain small amounts of goiterogenic substances that limit uptake of Iodine to the thyroid. In large amounts these "thyroid function inhibitors" can cause goiter and some researchers feel this may explain, at least in part, the perplexing correlation between millet consumption and goiter incidence in some of the developing countries where millet constitutes a significant part of the diet. In many of these countries another contributing factor may be a lack of sufficient dietary iodine.