See also: foods rich in iodine
As "most people know, the thyroid is the" internal thermostat of the "human organism". Its activity, in fact, leads to the synthesis and release of particular hormones, capable of heavily influencing various metabolic processes and favoring the growth and development of different organs, in particular the brain.
Since the synthesis of thyroid hormones depends on the availability of adequate amounts of iodine, most "thyroid supplements" contain this mineral or sources that are particularly rich in it (in general extracts of seaweed, such as fucus or laminaria). Selenium is also often present, an essential component of the enzyme system that transforms thyroxine (T4) into triiodothyronine (T3), playing a leading role in supporting thyroid function.
Iodine deficiency, iodine in food
Iodine is an essential micronutrient, present in the body in small quantities (15-20 mg). The daily losses are around 40 - 100 µg. For this reason, also taking into account the possible ingestion of goitrogen foods, we recommend an intake daily (in adults) of 150 µg. To ensure normal development of the baby, pregnant and lactating women must take more, respectively 220 µg / day and 290 µg / day.
In the case of an insufficient intake of iodine, the thyroid gland is unable to produce thyroid hormones in adequate quantities. A prolonged iodine deficiency causes a disease known as hypothyroidism, which has more or less important repercussions on health depending on the severity of the deficiency and the period in which it occurs (it is extremely important that pregnant women, nurses and children under the age of three take sufficient quantities of this element). Until a few decades ago, hypothyroidism due to iodine deficiency was quite widespread in some territories (including Italians) where the soil and its fruits are particularly poor in this mineral. Foods, in fact, contain extremely variable quantities of iodine and the richness of the soil determines the concentration of the mineral in fruit and vegetables, but also in the meat of the animals that are fed with them. The richest sources of iodine are sea fish and crustaceans; eggs, milk and meat also contain important quantities.
The best way to ensure the right amounts of iodine is to use iodine-enriched salt instead of the common one as part of a varied and balanced diet. The spread of this simple practice has helped to significantly reduce cases of hypothyroidism due to insufficient iodine intake.
Iodine and thyroid supplements
Prevention and side effects
To date, the toxic levels of iodine have not been exactly specified, also due to the fact that these are many times higher than the adequate doses. We have long known that an excess of iodine disturbs the thyroid gland and can cause some forms of hyperthyroidism; In this sense, the risk is greater the lower the basal intake level and the more rapidly the increase in dietary intake occurs. For this reason, the danger of an iodine excess also depends on the population considered; generally the upper tolerance limit is set at 500-600 µg / day.
Although iodine supplements - under medical supervision - are particularly useful for some individuals, it is therefore good not to abuse them.
When the thyroid is not working ...
It should be noted that calcium and iron supplements (quite common ingredients in various dietary supplements), can interfere with the absorption capacity of levothyroxine, a synthetic hormone (see eutirox) used in the treatment of hypothyroidism. To prevent this interaction is You need to take calcium supplements at least four hours before or after the drug.
In general, there are no specific diets for hypothyroidism, although many "experts" express opinions against it. The only recommendation is to take the medicine as prescribed by the doctor (usually on an empty stomach). The excess of fiber and some foods or drugs can in fact compromise their adequate absorption and as such must be spaced a few hours apart. Examples are antacids that contain aluminum or magnesium, some anti-ulcer drugs such as sucralfate, fiber supplements, soy flour, nuts and the aforementioned iron or calcium supplements.
Even more unscientific and dangerous is the belief that iodine supplements can replace the synthetic hormones used in the treatment of "hypothyroidism. Since the introduction of iodized salt, in fact, cases of hypothyroidism due to insufficient iodine intake have become very rare; for this reason and for other reasons, spontaneous recourse to iodine supplementation is strongly discouraged in all those cases in which the thyroid gland does not function properly (both in defect and in excess).
