Iodine deficiency has many causes. Micronutrient deficiency in pregnancy is mainly due to lack of food. The main source of iodine for a human is water and food. The demand of this element is increasing during the pregnancy. So the amount of iodine, which is taken before the pregnancy, may not be enough during the pregnancy. Iodine deficiency usually is developing during the pregnancy period. Some bodies can adapt to this situation and provides normal concentration of thyroid hormones which is necessary for the development of fetus. Fetal thyroid hormone production starts much later, when the initial development of the nervous system begins, for these hormones are necessary. So the child's normal development is entirely dependent on the mother's thyroid hormone output.
Compensate the iodine deficiency is virtually impossible with the diet. Most food contains very little amount of iodine. The diet does not ensure an equal distribution of iodine in the body. There are many different drugs, which are used for the prevention of mineral deficiency in pregnant women, but for the prevention it is better to use medicines containing iodine- they allow us to precisely control the amount of iodine in the body.