IODINE
 R.A.S HEMAT, MB;BCh, FRCSI, Dip.Urol.UCL.
Iodine (I) is strong oxidiser. Probable lethal dose is 2-4 g of free iodine. Iodine is an endocrine disruptor. Iodine is corrosive. Iodine in air can combine with water particles and precipitate into water or soils. Water solubility of iodine is determined by temperature (20ºC) and pressure (1 bar), and is relatively low. Iodine is applied for different purposes, such as iodine X-rays, which are applied to patients in large doses (up to 200 g), and are than excreted through urine. Iodine (I) occurs in many different forms that can be blue, brown, yellow, red, white, or colourless. Most forms of I easily dissolve in water or alcohol. Iodine has many uses.
- Molecular iodine is absorbed differently than iodide. Glaciers and heavy rainfall can deplete I from soils. Goitrogens interfere with the utilisation of I, e.g., cruciferous vegetables (like broccoli and radishes), soy, other halogens and certain toxic metals (mercury). Other halogens (fluorine, chlorine, and bromine) react in similar ways to I and may affect many biological processes. Fluorides, bromides, and perchlorates can all be problematic. Too much I induce goitre, which may not produce enough thyroid hormone for normal growth. Goat milk has higher concentrations of I than cow milk for equal deposition on feed. Breast milk is the primary source of iodine intake in nursing infants. The uptake of absorbed I by the thyroid gland results in 90% of the body iodine content residing in the thyroid gland.
Elemental iodine dissolves easily in chloroform and carbon tetrachloride. The deep blue colour of starch-iodine complexes is produced only by the free element. Tungsten iodide is used to stabilise the filaments in light bulbs. Extraction of I from seawater involves electrolysis. Iodine deficiency is the leading cause of preventable mental retardation, an effect that happens primarily when babies and small children are made hypothyroid by lack of the element. Iodine deficiency still a serious public health problem. Diabetes is an autoimmune disease, with links to the thyroid autoimmune diseases. Thyroid hormones are connected with remyelination. Multiple Sclerosis (MS) belongs to a family of diseases that seem to be linked to I and selenium (Se) deficiency. Iodine deficiency can have deleterious effects on the cardiovascular system (CVS). A higher iodine intake may benefit cardiovascular function. Tissues other than the thyroid gland can accumulate radioiodine, including salivary glands, gastric mucosa, choroid plexus, mammary glands, placenta, and sweat gland.
An acute iodide load can cause a decrease in thyroid hormone production in the thyroid gland; i.e., acute Wolff-Chaikoff effect. Thyroid hormones are essential to the development of the neuromuscular system and brain. An iodine-induced hypothyroid state can result in delayed or deficient brain and neuromuscular development of the newborn. Iodine is detected in every organ and tissue in the body. Iodine affects the ovarian production of oestrogen and also affects oestrogen receptors (ER). Iodine deficiency is related to ovarian cysts and ovarian cancer. Cyanobacteria (bluegreen algae) produce oxygen as a byproduct of photosynthesis. Cyanobacteria also have an affinity for I. These organisms use I as an antioxidant to protect themselves against the free radicals that oxygen progenies (superoxide anion, hydrogen peroxide, and hydroxyl radical). Kelp absorb increased amounts of I when placed under oxidative stress. Iodine induces apoptosis. Iodine removes the toxic halogens fluoride and bromide from the body. Iodism, an unpleasant brassy taste, runny nose, and acne-like skin lesions, is caused by the bromide that iodine extracts from the tissues. Oral exposure to excess iodide can produce allergic reactions in sensitive individuals.
Iodine deficiency during infancy may result in abnormal brain development and, consequently, impaired intellectual development. Selenium (Se) deficiency can exacerbate the effects of iodine deficiency. Deficiencies of vitamin A or iron may exacerbate the effects of iodine deficiency. Soybean isoflavones, genistein and daidzein inhibit thyroid hormone synthesis. Tobacco smoking may be associated with an increased risk of goitre in iodine-deficient areas. Potassium iodide may decrease the anticoagulant effect of warfarin. The clearance of particles from the respiratory tract is a dynamic process. Breast cancer may be also a concern with exposures to high levels of radioiodine after ablative therapy for hyperthyroidism because breast expresses NIS (iodine pump) and can transport and accumulate iodide. Oxidative deamination and decarboxylation of the alanine side chain of the iodothyronines represents 2% and 14% of total of T4 and T3 turnover, respectively. Filtered iodide is reabsorbed in the renal tubule. Orthomolecules can affect the toxicokinetics of iodine in children and adults. Agents that induce hepatic microsomal enzymes increase the activity of phenolic glucuronyl transferases that catalyse the conjugation of iodothyronines with glucuronic acid. Potassium iodate is used in salt iodisation, as an oxidising agent in analytical chemistry, and as a maturing agent and dough conditioner. Transport of I through surface water and groundwater is not greatly retarded by the soil, rock, and sediments over or through which these waters flow. Iodine in water exists as iodide and iodate. In rainwater, the relative proportion of iodide to iodate is 55:45. In surface waters, the proportion of iodide to iodate varies depending on microbial activity and the release of iodine species from terrestrial sources. There is evidence to suggest that elevated I intake, especially for populations where ambient I concentrations are low, can help to decrease the incidence of breast cancer and, in some cases, help to interfere with breast tumourigenesis. The transfer of I is bidirectional, and the I appears to freely diffuse between mammary gland and plasma.
August, 2009
The information in this article has been excerpted from the following books:
WATER, by R.A.S. HEMAT.
Note: Permission is granted to copy and redistribute this document electronically as long as it is unmodified. This article may not be sold in any medium, including electronic, CD-ROM, or database, or published in print, without the explicit, written permission of Dr. R. A. S. Hemat.
Clinical Orthomolecularism Classroom
Dr. R.A.S HEMAT declares no conflicts of interest or financial interests in any product or service mentioned in this article, including grants, employment, stock holdings, gifts, or honoraria.
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