Peter Hibberd, M.D., is a doctor whose advice is based on more than 28 years of hospital outpatient and inpatient experience. He is an experienced emergency medicine physician, surgeon, and consultant. Dr. Hibberd is certified by the American Board of Emergency Medicine. He is also a fellow and active member of the American Academy of Family Physicians, an active member of the American College of Emergency Physicians, and a member and fellow of the American Academy of Emergency Medicine. Dr. Hibberd has earned numerous national and international professional certifications, memberships, and awards.

What Can I Take For Iodine Supplementation?

Wednesday, 21 July 2010 12:41 PM

Question: I have many symptoms of hypothyroidism but my TSH is within normal limits according to the old parameters (five or over). I understand that the specifications have been lowered, so that a reading of three or over is considered high. Even if I received a diagnosis of hypothyroidism I would hesitate to take medication because I have atrial fibrillation/flutter. However, I do seem to have an iodine deficiency, based on the topical iodine skin test when absorption took place in less than two hours. Since I am an ovolactovegetarian and do not eat fish or other seafood, my only source of iodine is in salt. Aside from ingesting the small amount provided by kelp tablets, is there anything else I could take for iodine supplementation?

— Drena L.

Your prior test result, using the third generation TSH test, is not abnormal. Your TSH will need repeat testing to re-establish whether an abnormality is actually present. The TSH (thyroid stimulating hormone) is a pituitary hormone that is the brain's signal to the thyroid to produce more hormone, and is the most sensitive single thyroid function assay we use for evaluating an excess or deficiency of thyroid production.

This TSH assay has now evolved into a third generation, with differing normal reference ranges from prior generation tests. The normal range may vary depending upon the lab used, but is usually quoted as 0.4 to 4.50 mIU/L. These reference ranges are different (they vary but generally drop slightly) for those under 20 years of age and for those who are pregnant.

Iodine supplementation in the form of iodized salt is normally more than sufficient for normal thyroid hormone production. The presence of atrial fibrillation /flutter is perhaps an even more convincing reason to maintain normal thyroid function. It is a very good reason for appropriate replacement, but be careful to avoid over-supplementation by monitoring the TSH level.

Untreated hypothyroidism causes a drain on your heart and vascular system, and when severe can lead to congestive heart failure. You are unlikely to be deficient if you have no goiter and your TSH is normal, especially if you have used a third generation test and you do not have pituitary failure. Pituitary failure causes TSH secretion to be impaired or lost and the result is not enough stimulus to the thyroid and reduced or absent thyroid hormone production.

Iodine deficiency is most often seen in areas remote to the seaside and at high altitude since most environmental iodine occurs in seawater. It enters the atmosphere and then enters ground water and soil through rain near the sea. Since kelp is also a source of iodine, be careful not to over-supplement.

Excessive ingestion of iodine can be harmful, and can actually suppress thyroid hormone production and also cause an iodide goiter, GI irritation, and acne-like lesions. Excess iodine has been associated with both hypo and even hyperthyroidism. Scanning with radioiodine is useful for evaluating goiter and determining need for biopsy when evaluating of thyroid enlargement and nodules. The topical iodine skin test you report using is unreliable at best.

Iodine deficiency is rare in areas where iodized salt is used, and develops when intake is less than 20 micrograms per day. 100 micrograms of iodide daily is an adequate intake. There are 70 micrograms of iodide per gram of iodized table salt. Inadequate intake forces the thyroid gland to enlarge to concentrate iodide in itself, and results in a colloid goiter and usually an elevated TSH.

Iodine deficiency is best screened for by urinary iodine excretion when thyroid function deficiency and/or a goiter are detected. Since the TSH is an excellent screening test, urinary iodine is rarely measured. Thyroid symptoms of lethargy and fatigue are non- specific, and can be present in either over or underproduction of thyroid hormone, not to mention hundreds of other conditions.

I hope this helps. There is a large amount of misinformation about thyroid conditions around, and we owe it to ourselves to be sure our thyroid is functioning properly.

© HealthDay

1Like our page
Wednesday, 21 July 2010 12:41 PM
Newsmax Media, Inc.

The information presented on this website is not intended as specific medical advice and is not a substitute for professional medical treatment or diagnosis. Read Newsmax Terms and Conditions of Service.

Newsmax, Moneynews, Newsmax Health, and Independent. American. are registered trademarks of Newsmax Media, Inc. Newsmax TV, and Newsmax World are trademarks of Newsmax Media, Inc.

© Newsmax Media, Inc.
All Rights Reserved