Iodine is a chemical element that was discovered in 1811 by a scientist named Bernard Courtois. However, it was Gay-Lussac who gave it the Greek name iodes, meaning “the violet”, as he observed that when it was heated, it gave off violet vapours. Iodine is a chemical element with atomic number 53, located in the halogen group (group 7) of the periodic table of the elements. Its symbol is I (from the Greek ιώδης, iodes, “violet”) and it can be found as diatomic in a molecular form. Iodine has the lowest chemical reactivity among halogens. As with all other halogens (members of Group XVII in the periodic table), iodine forms diatomic molecules and thus forms the diiodide of molecular formula I2.
Functions of Iodine In The Body
This element is an indispensable nutrient for human beings, as it allows the thyroid gland to produce the hormones thyroxine and triiodothyronine, which are necessary for the production of various functions related to the utilization of nutrients in the body, as well as essential for the growth and development of the brain, among other tissues. Once iodine is ingested, it is rapidly absorbed by the intestine. Requirements are approximately 100-150 mg/day, although this varies with age, pregnancy, and lactation.
Disorders Due Imbalance
Iodine deficiency causes several complications, which is why its prevention is so important:
- Goitre: Excessive development of the thyroid gland, better known as goitre. It also causes imbalances in metabolism that can lead to fatigue and considerable weight gain.
- Myxedema: Myxedema is a tissue disorder characterized by oedema (accumulation of fluid), produced by infiltration of mucous substance in the skin, and sometimes in the internal organs, as a result of a malfunction of the thyroid gland (hypothyroidism).
- Consequences in pregnancy: Iodine deficiency in pregnant women can have a negative effect on the development of the fetus, and in other cases, it can even produce deficiencies in the fetus such as delay in the development of the central nervous system, as well as in the growth and maturation of the bones.
However, excess iodine in the body can even be severe too. Exposure of the body to large amounts of iodine sometimes results in alterations in thyroid function and can lead to both hyperthyroidism and hypothyroidism.
Hypothyroidism: Some symptoms may either be very vague (subclinical hypothyroidism) or appear over a prolonged period of time, being similar to other common medical problems and signs of ageing, so this is the reason why it is not unusual for the disease to be unnoticed. But if the pathology is left untreated, it can cause serious and potentially fatal complications. Besides, it may cause a disorder in cholesterol levels, hypertension and infertility.
Among the most common symptoms we find:
– Fatigue, drowsiness, and/or weakness.
– Intolerance to cold.
– Memory loss.
– Weight gain or greater difficulty in losing weight (despite a good diet and exercise).
– Abnormal menstruation and/or fertility problems.
– joint or muscle pain
– Thin, brittle hair or nails and/or dry, flaky skin.
Hyperthyroidism: Speeds up the sufferer’s metabolism.
Key symptoms are:
– Weight loss even though the person eats normally.
– Anxiety and irritability
– Rapid heart rate
– Prominent eyes
– Hair loss
– Feeling of weakness
– Increased frequency of bowel movements
– Rapid nail growth
– Thin, smooth skin
– Greater than normal sweating
– Abnormal menstruation
On the other hand, elemental iodine, I2, is toxic, and its vapour irritates the eyes and lungs. The maximum allowable concentration in the air when working with iodine is only 1 mg/m3. All iodides are toxic when taken in excess.
Iodine is a mineral that occurs naturally on the surface of the earth and is carried to the oceans and rivers by rainfall and is also found in the deep layers of the earth and the waste from oil wells. In general, the older and more eroded soils are, the lower the iodine content. For this reason, the content of this element in vegetables is very variable, since it depends on how much iodine is in the soil and the water with which they were cultivated. There are natural foods that have a higher concentration, since they absorb iodine from the sea, such as:
Also, milk and its derivatives contain this element, as well as meats and fruits, although in smaller quantities. The recommended daily amount in adults is 150 micrograms. Pregnant women need more (about 220 micrograms) and nursing mothers need 290 micrograms. The maximum tolerable intake is 1,100 micrograms. According to the Linus Pauling Institute, most diets give you less than 1,000 micrograms, so it would be strange to suffer from an excess of this element.