Sea vegetation, blue-green and green algae, and freshwater algae offer some of the best sources of iodine, which is also found in fruits, vegetables, and sprouted cereals. The amount of iodine in land vegetables depends on the amount of the mineral in the soil in which they are grown.
Iodine is needed to make thyroid hormones, which not only govern the rate and efficiency at which food is converted into energy, but also regulate physical and mental development.
Mild iodine deficiency leads to a lightly enlarged thyroid gland (or goiter), and is most likely to occur in women of reproductive age. Eating seaweed or sea vegetation supplements easily prevents the deficiency. Women with severe iodine deficiencies risk bearing children deficient in thyroid hormone; those children could, unless treated from birth with thyroxine, suffer from a form of retardation known as cretinism.