|
Iodine Requirement: Overview
Iodine is vital for good thyroid function, which in turn is essential for good health. Iodine deficiency was prevalent in the U.S. before the iodization of salt became a common practice in the 1920s [Journal of the American Dietetics Association 79 (1981): p.17].
Some individuals deliberately take kelp to try to lose weight by over stimulating the thyroid. This is a dangerous practice.
Causes and Development
Some otherwise healthful foods contain goitrogens - substances which can interfere with iodine uptake or hormone release from the thyroid gland. These foods are generally only a concern if iodine intake is low. Consumption of brassicas, such as cabbage, Brussels sprouts, broccoli and cauliflower, increase the requirements for iodine, especially if consumed raw. Soybeans, raw flaxseed, cassava (used in tapioca), sweet potatoes, lima beans, maize and millet also increase the requirements for iodine.Some individuals deliberately take kelp to try to lose weight by over stimulating the thyroid. This is a dangerous practice.
Diagnosis and Tests
An iodine intake of less than 20mcg per day is considered severe deficiency; 20-50mcg per day is considered moderate deficiency and 50-100mcg per day is considered mild deficiency.Treatment and Prevention
In the US, iodised salt is widely used and some other foods are fortified with iodine. In Canada all table salt is iodised. The UK has no iodine fortification strategy for plant foods or salt.Complications
Iodine deficiency during pregnancy and early infancy can result in cretinism (irreversible mental retardation and severe motor impairments).Iodine Need
Information On This Page
Signs and symptoms
Conditions that suggest it
Contributing risk factors
Conditions suggested by it
What else it can lead to
Recommendations
Signs, symptoms & indicators of Iodine Requirement:
Other Diagnostic Tests
Counter-indicators:
Symptoms - Skin - General
Conditions that suggest Iodine Requirement:
Hormones
Hyperthyroidism
| Hyperthyroidism may occur, particularly in elderly people, due to long term slight iodine deficiency as this may result in additional nodules on the thyroid. |
Symptoms - Female
Cysts in breasts
| Iodine treatment has been shown to reduce breast pain and cyst size. It is believed that iodine-deficient breast tissue starts a process in which small cysts develop and later harden. |
Tumors, Malignant
Ovarian Cancer
| Geographic differences in the rates of breast, endometrial and ovarian cancer appear to be linked to iodine intake, suggesting that low intake may produce increased gonadotrophin stimulation leading to a hyperestrogenic state characterized by a relatively low estriol : (estrone + estradiol) ratio which may increase the risk of these cancers. [Lancet, pp.890-1, 1976] |
Risk factors for Iodine Requirement:
Supplements and Medications
Counter-indicators:
Symptoms - Female
History of cysts in breasts
| Iodine treatment has been shown to reduce breast pain and cyst size. It is believed that iodine-deficient breast tissue starts a process in which small cysts develop and later harden. |
Symptoms - Food - Intake
Counter-indicators:
(High) dairy product consumption
| Consumers of dairy products generally receive sufficient iodine due to the use of iodine-containing disinfectants for cleaning dairy equipment, which leach into the milk. |
Symptoms - Food - Preferences
Vegetarian/vegan/raw food diet
| Iodine is typically undesirably low (about 50mcg per day compared to a recommended level of about 150mcg) in vegan diets unless supplements, iodine-rich seaweeds or foods containing such seaweeds are consumed. The low iodine levels in many plant foods reflect the low iodine levels in the soil. About half the iodine consumption of omnivores comes from dairy products. In October of 2003, one of many articles appeared on iodine deficiency in vegetarians and vegans [Annals of Nutrition and Metabolism 47 (2003): p.183]. Quoting from the paper: "One fourth of the vegetarians and 80% of the vegans suffer from iodine deficiency..." Only 9% of the meat-eaters were deficient. The milk drinkers were protected in part because iodine-containing disinfectants are used to clean the milk processing equipment. None of the vegetarians and vegans were eating sea vegetables, and none were using iodized salt - they were all using "natural" sea salt, which has significantly less iodine. |
Recommendations for Iodine Requirement:
Botanical
Bladderwrack
| The amount of iodine in bladderwrack is highly variable, probably as a result of different amounts of iodine in the water where it grows. A reasonable portion of bladderwrack may contain the U.S. adult recommended dietary allowance (RDA) of iodine (150mcg). |
Mineral
KEY
Weak or unproven link:
may suggest; may increase risk of
Strong or generally accepted link:
is often a sign or symptom of; often suggests; often increases risk of; often leads to
Definite or direct link:
increases risk of
Strong counter-indication:
often contraindicates; often decreases risk of
Definitely or absolutely counter-indicates:
decreases risk of
May be useful:
may help with
Very useful:
is highly recommended for
Last updated: Apr 25, 2013