Ask The Trainer #141 – Don’t Overlook Iodine

Ask The Trainer #141 - Don't Overlook Iodine


I’ve heard that iodine can help improve thyroid function, is that true? If so, what’s the best way to obtain iodine? Thanks.



Hi Kurt. You’ve heard correctly. The thyroid manufactures thyroid hormone T4 with iodine. Iodine also plays an important role in converting T4 into the highly active thyroid hormone T3. This hormone is vital in optimizing our metabolic rate. It’s also essential to the function of nearly every metabolic process of the body, including testosterone synthesis.

Iodine deficiencies cause hypothyroidism (underactive thyroid). This reduces your metabolic rate and inhibits testosterone synthesis. People suffering from hypothyroidism generally struggle with low energy levels, depression, blood circulation problems, and weight gain. In the case of men, it causes hypogonadism (low testosterone levels).


Studies conclude that men suffering from hypothyroidism and treated with exogenous thyroid hormones experienced significant increases in testosterone production. In some cases, it actually doubled their testosterone levels.

Researchers believe hypothyroidism initiates GnRH (Gonadotropin Releasing Hormone) insensitivity within the pituitary gland. This results in reduced levels of LH (Luteinizing Hormone), a hormone that stimulates Leydig cell production. These cells produce testosterone in the testes. In other words, less than optimal thyroid hormones levels will definitely result in some unpleasant symptoms.

There are a number of foods that are great sources of iodine. There are also iodine supplements available. However, why spend big money on them if you can get adequate amounts through foods?

Best Natural Iodine Sources

Seaweed: Statistically, Japanese people have far fewer incidents of hypothyroidism compared to Americans. One reason could be because of the amount of seaweed Japanese people consume regularly. Most Americans average 0.1-0.2 mgs of iodine per day. However, Japanese people take in an average of 1-3 mgs per day. Dried seaweed is so high in iodine just 100 grams contains up to 54 milligrams. That’s about 36,000% of the recommended daily allowance. In fact, just 1 gram per day satisfies an individual’s daily iodine requirements. Keep in mind that consuming any more than this could be toxic. In short, mega-dosing iodine is a really BAD idea!

Wild Caught Cod

This is one of the richest sources of iodine in the world. About 100 grams of wild cod yields around 100 mcg of iodine. That’s equivalent to 66% of the recommended daily allowance. You should ALWAYS opt for wild caught cod over farm-raised cod. Farm raised fish eat soy pellets. They also contain far fewer nutrients and have more pollutants and toxic heavy metals.


Although they are far from the iodine content of seaweed, potatoes are cheap and highly accessible. A medium sized potato with intact skin contains roughly 60 mcg of iodine. That equates to 40% of the recommended daily allowance.


Don’t wait for Thanksgiving! These delicious red berries are packed with antioxidants. People also use them to treat kidney stones, respiratory disorders, and urinary tract infections. Wait, there’s more! Cranberries are also a great natural source of iodine. A 50-gram serving yields around 150 mcg. That’s 100% of the recommended daily allowances. Not too shabby!

In conclusion, iodine is a very important mineral to help keep your thyroid hormones and testosterone levels in check. You can obtain plenty of this mineral if you focus on consuming iodine rich foods daily. If you’re unable to do so, simply purchase the supplemental form.

As I mentioned previously, taking too much iodine can be dangerous. Your best bet is to keep your levels in the ballpark of the recommended daily allowance or is 150 mcg per day. Please note that I said mcg and NOT mg! There is 1,000 mcg in 1 mg!

I hope this helps answer your question. I wish you all the best of success in your health and fitness endeavors!

Prove ‘Em Wrong,
Chad Shaw

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