Ask the Pharmacist: Factors that contribute to thyroid disease

Suzy Cohen
The American Thyroid Association says 20 million Americans have some form of thyroid disease. Are you one of them?

Many people already know that iodine deficiency is one reason for insufficient thyroid hormone, but you may not realize that much more is at play when it comes to total thyroid gland health.

There are several minerals that are essential for thyroid activation, for example, selenium and zinc. You don’t hear much about those two, however, a deficiency of either mineral will lead to poor activation of T4 to T3. Do you know what that means?

It means that T4 won’t convert to T3, and that would be a type of “hypothyroidism.” Put differently, if you can’t convert the T4 (inactive) to T3 which is active, then you will feel most of the symptoms of hypothyroidism. I discuss this in detail in my book entitled, “Thyroid Healthy: Lose Weight, Look Beautiful” and “Live the Life You Imagined.”

 Selenium and zinc are needed for the metabolic pathway that converts T4 to T3, and medications to restore the thyroid hormone never hit the root cause, although they may help if they have T3 in them.  But what if you are zinc deficient because you take a drug mugger of zinc, for example, you take famotidine every day for your reflux? Over time, you will likely become zinc deficient.

Let’s say you’re zinc deficient and feeling symptoms of hypothyroidism. Your doctor may see on your labs that you’re TSH is high, indicating that your thyroid hormones are low. And seeing that, your doctor may now prescribe Synthroid or Levothyroxine for you, which is a T4 drug. But what is going to happen now? Is that useful, do you think? Of course not, in this specific example, the zinc deficiency remains an obstacle to you getting well, and it will continue to prevent your new T4 drug from converting to T3. If you don’t have enough T3, you don’t feel well. 

The American Thyroid Association says 20 million Americans have some form of thyroid disease. Are you one of them? Courtesy: YouTube (courtesy)

In this case, the ideal scenario would be to know this information: To know the connection between zinc and thyroid hormone activation! So, the best resolution would be to recognize that you are taking a strong ‘drug mugger’ of zinc and restore the missing nutrient. For many people, this is a problem that persists for years and it shouldn’t because zinc levels are easy to test for.   

One more important point is that you have both regular T3 (which is active, it works!) and you have something called reverse T3 (noted as rT3).  Too much rT3 (and not enough active T3) will make you feel hypothyroid as well. It’s a factor that should be considered, and one that is easy to measure with a blood test. 

If you have further questions refer to my book, “Thyroid Healthy,” or speak to your endocrinologist about all the factors that contribute to thyroid disease. If this topic interests you, I have posted a more comprehensive article at my website,

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Suzy Cohen is a registered pharmacist. The information presented here is not intended to treat, cure or diagnose any condition. Visit