My favorite supplement for thyroid health

My favorite supplement for thyroid health

When I asked Dr. Nikolas Hedberg to name his favorite supplement for thyroid health, I was surprised by his answer and asked him to explain.

Are you always catching a cold? Do you have white spots on your fingernails? Do you have diarrhea? Is your hair falling out? Do you have atrial fibrillation? Do you have loss of smell or taste? Do you have acne, rashes or eczema? Are you feeling depressed, sluggish, or irritable? Do you have brain fog? Have you been diagnosed with ADHD or a learning disability? Do you have a low sex drive? Do you have a lack of appetite? Do you experience poor wound healing? Are you struggling to conceive? Do you have dandruff? Do you have trouble sleeping?

These could be signs you are one of the two billion people around the world estimated to have diets deficient in zinc. We are all different in terms of which supplements (and dosages) are right for our bodies, so speak to your doctor about whether zinc would be helpful for your thyroid health.

Written by Dr. Nikolas Hedberg

Of all the supplements out there for thyroid health, zinc may actually be my favorite because of its versatility and broad-spectrum use. Many supplements are only effective for one aspect of thyroid function, but Zinc is effective for many types of thyroid dysfunction. The T3 receptor requires zinc to function properly so a deficiency may result in subclinical hypothyroidism even though your lab tests look normal. Additionally, zinc is required for proper conversion of T4 into T3.

Zinc has many functions in the body but it most significantly impacts immune system function, hair growth, eye and skin health, digestive health, omega-3 fatty acid metabolism, growth and of course thyroid function. Zinc is involved in more than 300 known enzymes in the body! Zinc is also the second most abundant element in the body second only to iron. You must have adequate zinc levels to properly metabolize vitamin D and vitamin A, both of which are vital for thyroid health.

Proper thyroid hormone levels are required for zinc absorption and metabolism, and zinc is required for healthy thyroid function. This creates a vicious cycle if either one of these becomes out of balance.

What are the common signs & symptoms of zinc deficiency?

Slow wound healing

White spots on your fingernails

Hair loss (alopecia)

Poor immune system function (you catch everything that is going around and it takes forever to get better)

Impotence and low testosterone in men

Poor brain function

Insulin resistance (difficulty metabolizing carbohydrates)


Poor vision and hearing

Loss of taste

Low Free T4 and Free T3 levels (30% decrease in Zinc deficiency)

Elevated reverse T3

Elevated thyroid antibodies including thyroid peroxidase and anti-thyroglobulin

Low growth hormone levels


What are the best tests for zinc deficiency?

There is actually no generally accepted test for zinc status due to the many factors that can alter zinc in body fluids; however low levels of zinc in red blood cells, hair and urine may indicate deficiency. The alkaline phosphatase blood test which is part of a comprehensive metabolic profile I run on all patients can be low in zinc deficiency.   A zinc taste test is a quick and easy test we do in the office or it can be done at home with any liquid zinc supplement.

How to do a zinc taste test:

Put 2 tablespoons of liquid zinc into a cup and drink it into your mouth. Hold the liquid there for 30 seconds and then spit it out into the cup. Do not swallow the liquid as it can cause nausea.

Take note if there is any taste in your mouth or if you don’t taste anything at all. Follow these taste guidelines:

Taste Categories

One of the following categories should be applicable to your response of tasting two tablespoons of liquid zinc:

  1. No specific taste while holding the solution in your mouth indicates a very low zinc level. Take 90mg of zinc a day in divided doses for 60 days and then retest.
  2. A slight taste, resembling hydrogen peroxide, dry, mineral, furry or sweet indicates a low zinc level. Take 60mg a day for 60 days and then retest.
  3. A definite, though not strongly unpleasant, taste is noticed almost immediately and tends to intensify over time. Take 30mg a day for 60 days and then retest.
  4. An immediate, strong, metallic taste indicates adequate zinc levels. No zinc supplementation is necessary.

If you experience nausea with zinc supplements, try taking it at the end of the largest meal of the day.

How much should you take?

Research shows toxic doses between 100 to 300 milligrams a day so I recommend doses of 30, 60 or 90 milligrams a day depending on their zinc taste test and clinical presentation. A brand called Designs for Health is now available on Amazon and they make the Zinc Challenge and also a product called Zinc Supremeblank. Zinc competes with copper so supplementation above 40 milligrams a day can quickly cause a copper deficiency. Approximately 1 milligram of copper for every 30 milligrams of zinc will prevent copper deficiency. It is easiest to just use a properly formulated supplement that has copper added to the zinc product if you are taking more than 40 milligrams a day.

Excessive intake of calcium or iron can compete with zinc and cause a deficiency. Exposure to the toxic metal cadmium also competes with zinc, so be sure you are not being exposed to cadmium. Too much zinc can actually impair thyroid function so you should be absolutely certain you are deficient and taking the right dose if you have hypothyroidism. If you have low ferritin levels (iron stores), then you have to take the right balance of zinc and iron so you are not creating further deficiency of one or the other.

Zinc can prevent the absorption of thyroid medication so take it with lunch and dinner if you are taking medication first thing in the morning.

Consult with your doctor before supplementing with zinc.

What are the best foods rich in zinc?

The best foods that are highest in zinc are red meat, pork, chicken, oysters and whole grains. If you are following a gluten-free diet for Hashimoto’s or Graves’ disease, then you may be deficient in zinc if you aren’t eating enough meat. Compounds called phytates found in legumes, grains, nuts and seeds can inhibit the absorption of zinc.

Zinc-Adrenal-Thyroid Connection

Excessive cortisol levels will impair thyroid function in many ways including abnormal TSH levels, decreased conversion of T4 into T3, and elevated reverse T3. For those who are under a lot of stress, zinc supplementation has been shown to lower cortisol levels thus reducing the negative effects of stress on your thyroid.

Zinc deficiency is one of the most common problems I see associated with thyroid disorders in my practice despite the fact that it is so vital for healthy thyroid function. In some cases, profound improvements in health can be achieved simply by restoring zinc levels. Make sure you are thoroughly evaluated for zinc status if you have a thyroid disorder.

About Dr. Nikolas Hedberg

Dr. Nikolas R. Hedberg is a Board Certified Naturopathic Physician, Chiropractic Physician and a Diplomate of the American Clinical Board of Nutrition. His practice is the Immune Restoration Center in Asheville, NC where he focuses on thyroid disorders and autoimmune diseases.

READ NEXT: The 4 Best Supplements for Hashimoto’s Disease

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About Dana Trentini

Dana Trentini founded Hypothyroid Mom October 2012 in memory of the unborn baby she lost to hypothyroidism. This is for informational purposes only and should not be considered a substitute for consulting your physician regarding medical advice pertaining to your health. Hypothyroid Mom includes affiliate links including the Amazon Services LLC Associates Program.


  1. Lina Porterfield says


    I am trying all kind of vitamins…to help me with the fatigue. I will try zinc. Thanks for your advice!

  2. Amber Blue says

    I tried this and it burned immediately. What does that mean? I’ve rinsed and still suffer from burning metallic taste. Feels like acid.

  3. I have a mild case of hyperthyroidism — an overactive thyroid. I started anti-thyroid medication about 5 months ago, a very lose dose. This winter, I noticed that I was getting sick more often, and come to think of it, I’ve always had sinus problems and low-grade infections. I read about zinc deficiency and realized I had some of the symptoms, so I began taking additional OTC zinc supplements or lozenges. Within a few days I felt SO much better — it was amazing. I believe that my overactive thyroid was draining my immune system as well as key minerals from my body. I would like to read more about zinc and HYPERthyroidism. Thanks for this post!

  4. What brand of zinc supplement do you recommend taking if you do the zinc test and are deficient?

  5. What kind of zinc supplement do you recommend taking if you do the zinc test and are deficient?

  6. I lost 2 but I have one girl one boy ? But these posts made me realize how ignorant I wsa, how I never connected hypothyroidism with all the symptoms!! I started gluten free recently Dr. Said I have very tiny thyroid now due to “Hashimoto” I can’t reverse that back but al least I’m hoping for the other 30 symptoms to get better thanks to you?

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