What deficiency is known to cause goiter?

A goiter, which is an abnormal enlargement of the thyroid gland, is primarily caused by iodine deficiency. Iodine is an essential nutrient that the body requires to synthesize thyroid hormones, including thyroxine (T4) and triiodothyronine (T3). When there is insufficient iodine available in the diet, the thyroid gland cannot produce enough of these hormones, leading to a compensatory enlargement of the gland in an effort to increase hormone production. This condition results in a goiter.

In regions where iodine is lacking in the diet, such as areas far from the ocean or in populations that do not consume iodized salt, the incidence of goiter can be particularly high. Supplementation with iodine, such as through iodized salt, has significantly reduced the prevalence of goiter in many parts of the world.

While deficiencies in other nutrients, such as iron, fluoride, and zinc, can lead to other health issues, they do not directly cause goiter. Iron deficiency leads to anemia, fluoride deficiency affects dental health, and zinc deficiency can impair immune function and wound healing, but none of these deficiencies are linked to the enlargement of the thyroid gland in the same manner as iodine deficiency.