|
 |
|
|
|
For iodine, thyroid is job one
Iodine has one basic body job: to make the thyroid hormones that regulate your body's metabolism. Doesn't sound like much, but it is a major function. Those hormones are critical to your growth, nerve functions, and the cells' ability to use oxygen. If you don't have enough iodine, your thyroid tries to make more hormones, which can result in goiter (an uncomfortable and unhealthy swelling of the thyroid gland that manifests itself as a large lump on the neck).
Not to worry. You do get enough iodine -- American salt manufacturers add it to iodized salt at the rate of 400 micrograms (mcg) per teaspoon. But if you need an excuse for a nice dinner out, just mention that you can also get iodine from lobster.
Quick Facts About Iodine
- RDA is 150 to 200 mcg per day for adults.
- Natural food sources of iodine include lobster, oysters, shrimp, herring, canned salmon, dairy products, iodized salt, seaweed, cod, and cod liver oil (yum!).
- Signs of deficiency in childhood include depressed growth, delayed sexual development, mental retardation, and deafness.
- Adult deficiency symptom is goiter caused by hypothyroidism.
|
|
|
|
|
You May Need More Iodine If You:
- Have chronic malnutrition
- Live in a region where the soil is deficient in iodine
- Eat large amounts of food that can cause goiter, such as plants in the cabbage family -- broccoli, cabbage, kale, Brussels sprouts, kohlrabi, and cauliflower
Available Forms
- Individual supplement
- Combined with vitamins and other minerals
- Kelp and potassium iodide for those with sodium intake concerns
|
|
|
|
|
Chemical Forms of Iodine
- Potassium iodide
- Iodate salts
Comments on Iodine
- Iodine is a toxic and noxious gas. Iodide is the negatively charged form of iodine and is less damaging.
- Iodide is the biologically active form of iodine.
- Iodide is needed in the production of thyroid hormones.
- The thyroid contains 70% to 80% of all the iodide in the body.
- Most people obtain their iodide requirement from the salt in their food.
|
|
|
|
|
Known Benefits of Iodine
- Helps reduce toxicity of radioactive isotopes of iodine
- Participates in the functioning of the thyroid gland
- Prevents goiter
- Is an effective antiseptic
Iodine May Prevent These Signs of Deficiency
During pregnancy- Miscarriages
- Stillbirths
- Birth defects
- Cretinism
- Dwarfism
- Lack of muscular coordination
Birth defects, cretinism, and dwarfism are likely to occur at intakes below 25 mcg per day.
During childhood- Goiter
- Hypothyroidism
- Decreased mental ability
- Impaired physical development
During adulthood- Goiter
- Hypothyroidism
- Decreased mental ability
- Iodine-induced hyperthyroidism
Recommended Dosage Range of Iodine
- Our pharmacists suggest that healthy adults may take between 150 to 300 mcg daily to supplement a well-balanced diet.
- RDA values were set as the minimum needed to offset deficiency or disease, not as an actual value needed for optimum health.
- In the United States, the average daily consumption of iodine is 250 mcg for men,170 mcg for women.
Dietary Sources
Food Tips
- Seafoods are an excellent source of iodine.
- Seafood from salt-water sources are higher in iodine than fresh-water fish.
- Bread dough made with dough oxidizers or conditioners contain iodates and are also good sources of iodine.
- Potassium iodide is a good salt substitute for those reducing their salt intake.
| Foods High in Iodine |
|---|
Seaweed
Seafoods
Fish
Iodized salt
|
When and How to Take Iodine
- Swallow tablets whole with a glass of water.
- Take with meals or within 90 minutes of eating to enhance absorption.
What to Take with Iodine
Selenium is required for 5'-deiodinase, an essential enzyme.
What Not to Take with Iodine
Cassava interferes with iodide absorption because it contains cyanogen glucosides.
Storage
- Keep iodine in a cool, dry place away from direct sunlight and air.
- Don't store iodine in your bathroom medicine cabinet. Heat and moisture may make it less effective.
- Store safely out of children's reach.
Recommended Daily Allowance
| AGE/GROUP | RDA |
|---|
Infants
0 to 6 months
6 to 12 months
1 to 3 years
4 to 6 years
7 to 10 years
Males
11 to 14 years
15 to 18 years
19 to 24 years
25 to 50 years
51+ years
Females
11 to 14 years
15 to 18 years
19 to 24 years
25 to 50 years
51+ years
Pregnant
Lactating
1 to 6 months
6 to 12 months
|
mcg (micrograms)
40
50
70
90
120
150
150
150
150
150
150
150
150
150
150
175
200
200
|
|
|
|
|
|
|
Warnings
Consult a physician before use or do not use iodine if:- You are about to start a high-dose supplement program.
- You have a thyroid impairment. Iodide may produce goiter in those who are iodine deficient and increase their iodide intake.
Iodine May Have Interactions with
Lithium: if you are taking lithium, avoid taking iodine because the combination depresses the thyroid gland, resulting in abnormally low thyroid activity.
Side Effects of Iodine
- Iodide appears to have a wide margin of safety, but it is not recommended to ingest doses larger than 2 mg (2,000 mcg) per day.
Signs of Overdose
- Increased incidence of thyroid nodules
- Increased incidence of thyroid cancer
- Increased incidence of thyroiditis
- Marginal increase in hyperthyroidism when there is preexisting iodide deficiency
What to Do in Case of Overdose
Stop use and contact your physician immediately.
|
|
|
|
|
Sources & Further Reading
Books
- 1. Dell, BL and Sunde, RA.Handbook of Nutritionally Essential Mineral Elements. Marcel Dekker, Inc. New York, NY 1997.
- 2. Fauci et al. Harrison's Principles of Internal Medicine, Fourteenth Ed. McGraw-Hill Co., Inc. 1998.
- 3. Groff, JL, Gropper, SS, Hunt, SM.Advanced Nutrition and Human Metabolism, Second Ed. West Pub. Co. St. Paul, MN 1995.
Find more books on health and wellness at  barnesandnoble.com.
Articles
- 1. Cao XY; Jiang XM; Dou ZH; Rakeman MA; Zhang ML; ODonnell K; Ma T; Amette K; DeLong N; DeLong GR.Timing of vulnerability of the brain to iodine deficiency in endemic cretinism [see comments]. N Engl J Med, 1994 Dec, 331:26, 1739-44.
- 2. Cavalieri RR.Iodine metabolism and thyroid physiology: current concepts. Thyroid, 7(2):177-81 1997 Apr.
- 3. Delange F.The disorders induced by iodine deficiency. Thyroid, 1994 Spr, 4:1, 107-28.
- 4. Dunn JT; Semigran MJ; Delange F.The prevention and management of iodine-induced hyperthyroidism and its cardiac features. Thyroid, 1998 Jan, 8:1, 101-6.
- 5. Elnagar B; Eltom A; Wide L; Gebre Medhin M; Karlsson FA.Iodine status, thyroid function and pregnancy: study of Swedish and Sudanese women. Eur J Clin Nutr, 1998 May, 52:5, 351-5.
- 6. Galofr? JC; Fern?ndez Calvet L; R?os M; Garc?a Mayor RV.Increased incidence of thyrotoxicosis after iodine supplementation in an iodine sufficient area. J Endocrinol Invest, 1994 Jan, 17:1, 23-7.
- 7. Kahaly GJ; Dienes HP; Beyer J; Hommel G.Iodide induces thyroid autoimmunity in patients with endemic goitre: a randomised, double-blind, placebo-controlled trial. Eur J Endocrinol, 1998 Sep, 139:3, 290-7.
- 8. Kalk WJ; Sitas F; Patterson AC.Thyroid cancer in South Africa--an indicator of regional iodine deficiency. S Afr Med J, 87(6):735-8 1997 Jun.
- 9. Liesenk?tter KP; G?pel W; Bogner U; Stach B; Gr?ters A.Earliest prevention of endemic goiter by iodine supplementation during pregnancy. Eur J Endocrinol, 1996 Apr, 134:4, 443-8.
- 10. Paschke R; Vogg M; Winter J; Wawschinek O; Eber O; Usadel KH.The influence of iodine on the intensity of the intrathyroidal autoimmune process in Graves' disease. Autoimmunity, 1994, 17:4, 319-25.
- 11. Rasooly L; Rose NR; Saboori AM; Ladenson PW; Burek CL.Iodine is essential for human T cell recognition of human thyroglobulin. Autoimmunity, 1998, 27:4, 213-9.
- 12. Reinhardt W; Kohl S; Hollmann D; Klapp G; Benker G; Reinwein D; Mann K.Efficacy and safety of iodine in the postpartum period in an area of mild iodine deficiency. Eur J Med Res, 1998 Apr, 3:4, 203-10.
- 13. Stanbury JB; Ermans AE; Bourdoux P; Todd C; Oken E; Tonglet R; Vidor G; Braverman LE; Medeiros-Neto G.Iodine-induced hyperthyroidism: occurrence and epidemiology. Thyroid, 8(1):83-100 1998 Jan.
| |
|
