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CL Answers (19)

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Clinical Updates (13)

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Thyroid Product Caution

Use of a popular thyroid product may interfere with important thyroid tests, according to recent reports. Get the details in our article about Supplements and Hypothyroidism.


Soy Can Affect Thyroid

Daily intake of soy isoflavones (as found in soy protein and soy isoflavone supplements) can affect thyroid hormone levels — even in people with normal thyroid function, according to a recent study. For details, see the "Concerns and Cautions" section of the Menopause Supplements Review and the Protein Supplements Review.

Concern With Ashwagandha

Ashwagandha can increase thyroid hormone levels, resulting in thyroid toxicity, even in people without a history of thyroid disease. Read about a recent case and learn symptoms to look for in the Concerns and Cautions section of the Ashwagandha Supplements Review. Also see our Top Pick among ashwagandha supplements.

Warning: Biotin Can Affect Thyroid Tests

Vitamins that contain megadoses of biotin (vitamin B7) can affect thyroid tests, according to recent studies. This can lead to an incorrect diagnosis of hyperthyroidism and improper treatment. See the "Biotin" section of the B Vitamin Supplements Review >>

Ashwagandha & Thyroid Function

Ashwagandha extract improved thyroid hormone levels in men and women with subclinical hypothyroidism in a new study. See the details in the "What It Does" section of our Ashwagandha Supplements Review -- which includes our Top Pick among ashwagandha supplements.

Iodine Pills for Radiation Protection

Due to concerns relating to the safety of nuclear reactors and potential use of nuclear weapons in the war in Ukraine, demand for radioprotective iodine products has jumped.

Potassium iodide and potassium iodate can help protect the thyroid from the effects of radioactive iodine from the air, water, and foods after a nuclear event. But who should be taking these products, when should they be taken, and how much should be taken?

Find out in our review of Potassium Iodide and Iodate Radioprotective Pills, and see our Top Picks among products (and where to currently get them).


Vitamin D & Autoimmune Disease

A major study suggests that supplementing with vitamin D may reduce the risk of some autoimmune diseases, such as rheumatoid arthritis. Fish oil may also have some benefit. But there are important caveats to the findings, and thyroid disease and psoriasis appear to be impacted. Use the above links for details.

Fluoride and Hypothyroidism?

Can fluoride in toothpaste affect thyroid function? Find out what research suggests in our updated article about what to look for, or avoid, in toothpaste.

Does Ginkgo Cause Cancer?

According to a new study from the government, animals given an extract of Ginkgo biloba for two years developed cancers of the thyroid and liver. Should you be concerned? See the "Concerns and Cautions" section of the Ginkgo Biloba Supplements Review for more information, as well our assessment of ginkgo's usefulness, and our tests of ginkgo supplements

How Good Is Generic Thyroid Medication?

How well do people with hypothyroidism do on generic versions of levothyroxine (Synthroid)? We've added new information about this to our article about levothyroxine and dietary supplements.

Don't Take Calcium With Thyroid Hormone

A study showed negative effects of taking calcium too soon after taking levothyroxine (Synthroid). For details on how to safely take this combination, see the update in the Concerns and Cautions section of the Calcium Supplements Review. (Also see our Top Picks for calcium.)

Recalls & Warnings (100)

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