Iodine: benefits, dosage, contraindications
Other name(s)
I
Family or group:
Minerals and trace elements
Indications
Scoring methodology
EFSA approval.
Iodine deficiency ✪✪✪✪✪
The slightest iodine deficiency causes serious functional abnormalities by disrupting basal metabolism, due to a decrease in thyroid hormones (hypothyroidism): fatigue, tendency to feel cold, slight weight gain, and fine, brittle hair. nnIodine deficiency manifests as the development of a thyroid goiter, growth retardation, mental disorders (cretinism) and slowed brain development, especially in children before the age of 2. This deficiency can also lead to decreased fertility as well as increased miscarriages and perinatal mortality. nnThe recommended daily dose according to EFSA varies by age, from 70 µg/day up to a maximum of 600 µg/day.nn
Posologie
Oral administration
150 - 600 µg
Potassium iodide
Thyroid balance ✪✪✪✪✪
Iodine contributes to the normal production of thyroid hormones and to the normal functioning of the thyroid. Indeed, the thyroid gland in humans concentrates about 30% of the body's iodine for the synthesis of thyroid hormones. Iodine is an essential component of the thyroid hormones (thyroxine (T4) and triiodothyronine (T3)) that control many biochemical reactions. nnIodine deficiency or excess can lead to hypothyroid conditions.nn
Posologie
Oral
150 - 600 µg
Adults
Iodine-deficiency disorders
Potassium iodide in dermatology: a 19th century drug for the 21st century-uses, pharmacology, adverse effects, and contraindications
Value and pitfalls in iodine fortification and supplementation in the 21st century
Iodine: deficiency and therapeutic considerations
Child development ✪✪✪✪✪
Iodine contributes to normal cognitive function, normal nervous system function, and to the normal growth of children. Indeed, iodine deficiency leads to growth retardation, mental disorders (cretinism), and slowed brain development, especially in children under 2 years of age. nn
Posologie
Oral
70 - 500 µg
Children
Potassium iodide in dermatology: a 19th century drug for the 21st century-uses, pharmacology, adverse effects, and contraindications
Scientific Opinion on the Substantiation of a health claim related to Iodine and the growth of children pursuant to Article 14 of Regulation (EC) No 1924/2006
Value and pitfalls in iodine fortification and supplementation in the 21st century
Iodine: deficiency and therapeutic considerations
Fetal development ✪✪✪✪✪
A significant iodine deficiency during intrauterine life leads to abnormal brain growth and maturation, resulting in a picture of cretinism.
Posologie
Orally
200 - 600 µg
Pregnant women
Potassium iodide in dermatology: a 19th century drug for the 21st century-uses, pharmacology, adverse effects, and contraindications
Does maternal iodine supplementation during the lactation have a positive impact on neurodevelopment of children? Three-year follow up of a randomized controlled trial
Value and pitfalls in iodine fortification and supplementation in the 21st century
Iodine: deficiency and therapeutic considerations
Cognitive performance ✪✪✪✪✪
It has been suggested that iodine deficiency, primarily in children and young adults, leads to dysregulation of certain brain proteins in specific regions of the brain, a reduction in mRNA expression in axons of the anterior commissure, and changes in dendrite size, which may result in premature cell apoptosis.nnFurthermore, iodine deficiency may lead to a reduction in the size of cerebellar cells and decreased myelination throughout the central nervous system, and may therefore be associated with brain atrophy and white matter lesions.nnOne study highlighted an interesting link between low iodine intake and internal brain atrophy, as represented by enlarged ventricles.nnThe WHO describes a wide range of disorders caused by iodine deficiency, including impaired mental and physical development in children and adolescents, as well as impaired mental functions and reduced cognitive abilities in people of all ages.nn
Posologie
Orally
150 µg
Scientific Opinion on the substantiation of health claims related to iodine and contribution to normal cognitive and neurological function (ID 273), contribution to normal energy-yielding metabolism (ID 402), and contribution to normal thyroid function and production of thyroid hormones (ID 1237) pursuant to Article 13(1) of Regulation (EC) No 1924/2006
Leg ulcer ✪✪✪✪✪
Analysis of clinical studies suggests that applying cadexomer iodine to venous leg ulcers for 4 to 6 weeks, combined with compression, increases the rate of complete healing compared with standard treatment. However, the use of cadexomer iodine was associated with more adverse effects than standard care.
Posologie
Topical
6 - weeks
cadexomer iodine, povidone-iodine
Wound ✪✪✪✪✪
Iodine has been used for more than a century as a topical antiseptic in the treatment of superficial wounds and is still widely used for this indication. It is a very effective means of disinfecting intact skin and minor wounds. Povidone-iodine preparations have replaced older iodine solutions and are now the most commonly used form. The results of a systematic review of 27 randomized clinical trials on wound care in chronic and acute conditions showed that iodine has equivalent or superior benefits compared with other types of dressings (paraffin dressings, dextranomer or zinc paste) and other antiseptic agents (silver sulfadiazine cream or chlorhexidine dressings). Studies also noted that the use of topical iodine did not affect thyroid function, did not cause allergic reactions, and did not reduce the rate of wound healing.
Posologie
Topical
povidone-iodine
Mastalgia ✪✪✪✪✪
A placebo-controlled trial showed that taking molecular iodine at 3 to 6 mg per day for 5 months significantly reduces breast pain and tenderness in women with cyclic mastalgia.
Posologie
Oral
3 - 6 mg
5 - months
Women
molecular iodine
Fibrocystic disease of the breast ✪✪✪✪✪
Clinical research shows that iodine intake markedly improves the subjective and objective symptoms of fibrocystic disease of the breast, including pain and fibrosis. Molecular iodine appears to be more effective and better tolerated than other forms. Molecular iodine has been used at a dose of 70-90 mcg/kg per day for 4-18 months.
Posologie
Oral
4.9 - 6 mg
18 - months
Women
molecular iodine
Properties
Essential
Iodine is essential for the synthesis of thyroid hormones. Indeed, the human thyroid gland concentrates about 30% of the body's iodine for the synthesis of thyroid hormones. Smaller amounts of iodine are found in the salivary glands, the breasts, the choroid plexus and the gastric mucosa. Iodine is an indispensable component of thyroid hormones (thyroxine (T4) and triiodothyronine (T3)) that control many biochemical reactions, including protein synthesis and enzymatic processes, and are responsible for the myelination of the developing central nervous system. In people with hyperthyroidism, iodine inhibits the release and synthesis of thyroid hormone. Iodine deficiency or excess can lead to thyroid insufficiency. Severe iodine deficiency during intrauterine life causes abnormal brain growth and maturation, resulting in cretinism. As such, iodine is the trace element whose deficiency has the greatest impact on human life.
Usages associés
Antibacterial
Iodine is used topically as an antiseptic, in alcohol (iodine tincture) or in the form of povidone-iodine (Betadine®). It is capable of oxidizing organic substrates and killing microorganisms.
Usages associés
Hormonal metabolism
In euthyroid individuals (those with normal thyroid function), normal doses of iodine have no significant effect, whereas higher pharmacological doses appear to have a transient suppressive effect. Indeed, 500 µg of iodine or more (in addition to dietary intake) appear to have a slight inhibitory effect on thyroid function in otherwise healthy people, and consequently a decrease in T3 and T4 (thyroid hormones) with an increase in thyroid-stimulating hormone (TSH).
Usages associés
Neurological
Thyroid hormone is responsible for the myelination of the developing central nervous system. Consequently, iodine deficiency is associated with intellectual disability which, in some cases, can be severe. nn
Usages associés
Antioxidant
In certain tissues, iodine may have an antioxidant effect. It is thought that in the presence of hydrogen peroxide, peroxidase and certain unsaturated fatty acids, iodine donates an electron, thereby reducing damage caused by oxygen free radicals.nn
Safe dosage
Infant 7 to 11 months: 70 µg
Child 1 to 3 years: 90 µg - 200 µg
Child 4 to 6 years: 90 µg - 250 µg
Child 7 to 10 years: 90 µg - 300 µg
Child 11 to 14 years: 120 µg - 450 µg
Child 15 to 17 years: 130 µg - 500 µg
Adult 18 years and older: 150 µg - 600 µg
Pregnant women 18 years and older: 200 µg - 600 µg
Breastfeeding women 18 years and older: 200 µg - 600 µg
Interactions
Médicaments
Antithyroid: strong interaction
Concomitant use of antithyroid drugs and iodine may enhance the antithyroid effect and lead to hypothyroidism.
Antihypertensive: moderate interaction
Antihypertensives belonging to the families of angiotensin-converting enzyme inhibitors (ACE inhibitors) and angiotensin II receptor antagonists (ARBs) can increase potassium levels. Concomitant use of these drugs and potassium iodide increases the risk of hyperkalemia.
Diuretics: moderate interaction
Potassium-sparing diuretics can increase potassium levels. Concomitant use of these drugs and potassium iodide increases the risk of hyperkalemia.
Amiodarone: moderate interaction
Amiodarone contains iodine. Concomitant use of iodine and amiodarone may increase iodine levels and lead to impaired thyroid function.
Lithium: moderate interaction
Lithium can inhibit thyroid function. Concomitant use of iodine and lithium may have synergistic hypothyroid effects.
