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Health Condition

Hypothyroidism

  • Iodine

    Iodine deficiency and excessive iodine intake can both lead to hypothyroidism, so ask your doctor if supplementing with iodine is right for you.

    Dose:

    Consult a qualified healthcare practitioner
    Iodine
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    The relationship between iodine and thyroid function is complex. Iodine is required by the body to form thyroid hormone, and iodine deficiency can lead to goiter and hypothyroidism.1 Severe and prolonged iodine deficiency can potentially lead to serious types of hypothyroidism, such as myxedema or cretinism. It is estimated that one and a half billion people living in 118 countries around the world are at risk for developing iodine deficiency.2

    Today, most cases of iodine deficiency occur in developing nations. In industrialized countries where iodized salt is used, iodine deficiency has become extremely rare. On the other hand, iodine toxicity has become a concern in some of these countries.3 Excessive iodine intake can result in either hypothyroidism4 or hyperthyroidism (overactive thyroid).5 Sources of iodine include foods (iodized salt, milk, water, seaweed, ground beef), dietary supplements (multiple vitamin-mineral formulas, seaweed extracts), drugs (potassium iodide, amiodarone, topical antiseptics), and iodine-containing solutions used in certain laboratory tests. Many nutritional supplements contain 150 mcg of iodine. While that amount of iodine should prevent a deficiency, it is not clear whether supplementing with iodine is necessary or desirable for most people. Those wishing to take a nutritional supplement containing iodine should consult a doctor.

  • Bladderwrack

    Bladderwrack is a type of brown seaweed that contains iodine. Hypothyroidism due to insufficient iodine intake may improve with bladderwrack supplementation.

    Dose:

    Refer to label instructions
    Bladderwrack
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    Bladderwrack (Fucus vesiculosus) is a type of brown seaweed that contains variable amounts of iodine.6 Hypothyroidism due to insufficient intake of iodine may possibly improve with bladderwrack supplementation, though human studies have not confirmed this.

  • Selenium

    Selenium plays a role in thyroid hormone metabolism. People who are deficient in selenium may benefit from supplementation.

    Dose:

    Refer to label instructions
    Selenium
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    Selenium plays a role in thyroid hormone metabolism. Severe selenium deficiency has been implicated as a possible cause of goiter.7 Two months of selenium supplementation in people who were deficient in both selenium and iodine was shown to induce a dramatic fall of the already impaired thyroid function in clinically hypothyroid subjects.8 Researchers have suggested that people who are deficient in both selenium and iodine should not take selenium supplements without first receiving iodine or thyroid hormone supplementation.9 There is no research demonstrating that selenium supplementation helps people with hypothyroidism who are not selenium-deficient.

  • Thyroid Extracts

    Thyroid extract is used by some doctors as an alternative to synthetic thyroid hormones. One doctor reported that thyroid extract worked better than standard thyroid preparations for many of his patients with hypothyroidism.

    Dose:

    Refer to label instructions
    Thyroid Extracts
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    Desiccated thyroid, also called thyroid extract (e.g., Armour Thyroid), is used by some doctors as an alternative to synthetic thyroid hormones (such as thyroxine [Synthroid or other brand names]) for people with hypothyroidism. Thyroid extract contains two biologically active hormones (thyroxine and triiodothyronine), whereas the most commonly prescribed thyroid-hormone preparations contain only thyroxine. One study has shown that the combination of the two hormones contained in desiccated thyroid is more effective than thyroxine alone for those with hypothyroidism.10 One doctor reported that thyroid extract worked better than standard thyroid preparations for many of his patients with hypothyroidism.11 Glandular thyroid products, which are available from health food stores, have had most of the thyroid hormone removed and would therefore not be expected to be effective for people with hypothyroidism. Intact desiccated thyroid is available only by prescription. Hypothyroidism sufferers who want to use desiccated thyroid must first consult with a physician.

  • Vitamin A

    People with hypothyroidism may have an impaired ability to convert beta-carotene to vitamin A. For this reason, some doctors suggest supplementing with vitamin A.

    Dose:

    Refer to label instructions
    Vitamin A
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    People with hypothyroidism have been shown to have an impaired ability to convert beta-carotene to vitamin A.12,13 For this reason, some doctors suggest taking supplemental vitamin A (approximately 5,000–10,000 IU per day) if they are not consuming adequate amounts in their diet.

  • Vitamin B3 (Niacin)

    Vitamin B3 (niacin) supplementation may decrease thyroid hormone levels.

    Dose:

    Refer to label instructions
    Vitamin B3 (Niacin)
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    Preliminary data indicate that vitamin B3 (niacin) supplementation may decrease thyroid hormone levels. In one small study, 2.6 grams of niacin per day helped lower blood fat levels.14 After a year or more, thyroid hormone levels had fallen significantly in each person, although none experienced symptoms of hypothyroidism. In another case report, thyroid hormone levels decreased in two people who were taking niacin for high cholesterol and triglycerides; one of these two was diagnosed with hypothyroidism.15 When the niacin was discontinued for one month, thyroid hormone levels returned to normal.

  • Zinc

    In people with low zinc, supplementing with zinc may increased thyroid hormone levels.

    Dose:

    Refer to label instructions
    Zinc
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    Laboratory animals with severe, experimentally induced zinc deficiency developed hypothyroidism, whereas moderate zinc deficiency did not affect thyroid function.16 In a small study of healthy people, thyroid hormone (thyroxine) levels tended to be lower in those with lower blood levels of zinc. In people with low zinc, supplementing with zinc increased thyroxine levels.17 One case has been reported of a woman with severe zinc deficiency (caused by the combination of alcoholism and malabsorption) who developed hypothyroidism that was corrected by supplementing with zinc.18 Although the typical Western diet is marginally low in zinc,19 additional research is needed to determine whether zinc supplementation would be effective for preventing or correcting hypothyroidism.

What Are Star Ratings
×
Reliable and relatively consistent scientific data showing a substantial health benefit.
Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.

References

1. Thilly CH, Swennen B, Bourdoux P, et al. The epidemiology of iodine-deficiency disorders in relation to goitrogenic factors and thyroid-stimulating-hormone regulation. Am J Clin Nutr 1993;57(2 Suppl):267S-70S.

2. Delange F. Risks and benefits of iodine supplementation. Lancet 1998;351:923-4.

3. Contempre B, Dumont JE, Ngo B, et al. Effect of selenium supplementation in hypothyroid subjects of an iodine and selenium deficient area: the possible danger of indiscriminate supplementation of iodine-deficient subjects with selenium. J Clin Endocrinol Metab 1991;73:213-5.

4. Chow CC, Phillips DIW, Lazarus JH, Parkes AB. Effect of low dose iodide supplementation on thyroid function in potentially susceptible subjects: are dietary iodide levels in Britain acceptable? Clin Endocrinol 1991;34:413-6.

5. Stewart JC, Vidor GI. Thyrotoxicosis induced by iodine contamination of food: a common unrecognized condition? Br Med J 1976;1:372-5.

6. Norman JA, Pickford CJ, Sanders TW, et al. Human intake of arsenic and iodine from seaweed based food supplements and health foods available in the UK. Food Addit Contam 1987;5:103-9.

7. Thilly CH, Swennen B, Bourdoux P, et al. The epidemiology of iodine-deficiency disorders in relation to goitrogenic factors and thyroid-stimulating-hormone regulation. Am J Clin Nutr 1993;57(2 Suppl):267S-70S.

8. Contempre B, Dumont JE, Ngo B, et al. Effect of selenium supplementation in hypothyroid subjects of an iodine and selenium deficient area: the possible danger of indiscriminate supplementation of iodine-deficient subjects with selenium. J Clin Endocrinol Metab 1991;73:213-5.

9. Vanderpas JB, Contempre B, Duale NL, et al. Selenium deficiency mitigates hypothyroxinemia in iodine-deficient subjects. Am J Clin Nutr 1993 Feb;57(2 Suppl):271S-275S [review].

10. Bunevicius R, Kazanavicius G, Zalinkevicius R, Prange AJ Jr. Effects of thyroxine as compared with thyroxine plus triiodothyronine in patients with hypothyroidism. N Engl J Med 1999;340:424-9.

11. Gaby AR. Treatment with thyroid hormone. JAMA 1989;262:1774 [letter].

12. Smolle J, Wawschinek O, Hayn H, Eber O. Vitamin A and carotene in thyroid disease. Acta Med Austriaca 1983;10:71-3 [in German].

13. Aktuna D, Buchinger W, Langsteger W, et al. Beta-carotene, vitamin A and carrier proteins in thyroid diseases. Acta Med Austriaca 1993;20:17-20 [in German].

14. Shakir KMM, Kroll S, Aprill BS, et al. Nicotinic acid decreases serum thyroid hormone levels while maintaining a euthyroid state. Mayo Clin Proc 1995;70:556-8.

15. O'Brien T, Silverberg JD, Nguyen TT. Nicotinic acid-induced toxicity associated with cytopenia and decreased levels of thyroxine-binding globulin. Mayo Clin Proc 1992;67:465-8.

16. Fujimoto S, Indo Y, Higashi A, et al. Conversion of thyroxine into tri-iodothyronine in zinc deficient rat liver. J Pediatr Gastroenterol Nutr 1986;5:799-805.

17. Hartoma TR, Sotaniemi EA, Maattanen J. Effect of zinc on some biochemical indices of metabolism. Nutr Metab 1979;23:294-300.

18. Weismann K, Roed-Petersen J, Hjorth N, Kopp H. Chronic zinc deficiency syndrome in a beer drinker with a Billroth II resection. Int J Dermatol 1976;15:757-61.

19. Wolf WR, Holden J, Greene FE. Daily intake of zinc and copper from self selected diets. Fed Proc 1977;36:1175.

20. Galland L. Biochemical abnormalities in patients with multiple chemical sensitivities. Occup Med 1987;2:713-20 [review].

21. Robins JM, Cullen MR, Connors BB, Kayne RD. Depressed thyroid indexes associated with occupational exposure to inorganic lead. Arch Intern Med 1983;143:220-4.

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The information presented by Healthnotes is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2019.

Drugs used to treat HYPOTHYROIDISM. Select drug name to view medication information and pricing