4 Subtle Signs of Iodine Deficiency That Show Up in Your Skin, Hair & Nails

If your skin feels dry no matter what products you use, your hair seems thinner than it used to be, or your nails have developed strange ridges seemingly overnight—you might be dealing with more than just aging.

These subtle changes can be early signs of an iodine deficiency. And here's the kicker: you don't have to live in a developing country or eat a poor diet to be affected. Many healthy, wellness-conscious women—especially those over 40—are walking around with low iodine levels and don’t even know it.

Iodine is essential for thyroid hormone production, and your thyroid is the control center for your metabolism, energy, skin renewal, hair growth, and even body temperature regulation. When your iodine levels are low, your thyroid struggles, and the symptoms can show up in surprisingly subtle ways.

Why Iodine Deficiency Is So Common Now

Back in the day, iodine deficiency was a major public health issue, so iodine was added to table salt. But today, many people are choosing sea salt or Himalayan salt (which aren't iodized), eating more whole foods with less processed salt, or avoiding sodium altogether for heart health. The result? Unintentional iodine deficiency.

Women are particularly vulnerable due to hormonal changes in perimenopause and menopause. Add in the fact that iodine isn’t found in many plant-based foods, and it’s easy to see how deficiencies happen.

Even mild iodine deficiency can have big consequences, especially when left unchecked. Below are four early signs to watch for.

1. You're Always Cold (Especially Hands and Feet)

If you find yourself constantly reaching for a sweater or warming your hands under hot water, it could be your thyroid struggling to regulate body temperature.

Low iodine means less thyroid hormone, and that slows down your metabolism and heat production. If you’re cold even when others are comfortable, especially in your hands and feet, this could be an early red flag.

2. Vertical Ridges on Your Nails

Nail changes are often overlooked, but vertical ridges (running from base to tip) can be an early sign of slowed cell regeneration caused by low thyroid function. If your nails feel more brittle or textured than usual, and you’ve ruled out iron deficiency, it might be time to look at your iodine levels.

3. Thinning or Brittle Hair

Hair follicles are highly sensitive to changes in thyroid hormones. When iodine is low and your thyroid isn't functioning optimally, the hair growth cycle is disrupted. You may notice increased shedding, weaker strands, or a thinner ponytail. This hair loss is often subtle and gradual, making it easy to miss.

4. Dry or Puffy Skin That Doesn’t Improve

If your skincare routine suddenly stops working, or your skin looks dull, flaky, or puffy, it may be due to low thyroid hormone levels. These symptoms don’t usually respond to topical treatments because the root issue is internal—your skin cells aren’t renewing properly.

How to Support Healthy Iodine Levels

The best food sources of iodine are seaweed, seafood, eggs, and iodized salt. But if you eat a mostly whole food diet, avoid seafood, or follow a low-sodium or plant-based lifestyle, a supplement might be necessary.

My go-to recommendation is J. Crow’s Lugol’s Solution of Iodine. It contains both iodine and potassium iodide, supports thyroid hormone production, and is easy to adjust based on your needs. Most people do well starting with 2 drops per day (about 2.5mg of iodine), but it’s always best to work with a practitioner.

How to Know for Sure

To test your iodine status, ask your doctor for an iodine test. You can also check your thyroid panel (TSH, free T3, and free T4) to see how your thyroid is functioning.

If you’ve been dealing with low energy, brittle hair, cold hands, or stubborn skin issues, these could be subtle signs your thyroid—and your iodine levels—need support.

Final Thoughts

Iodine deficiency is more common than most people think, and it often hides behind symptoms that are easy to brush off or misattribute to aging. By paying attention to the small things your body is trying to tell you, you can get ahead of more serious thyroid issues before they start.

If you're curious about other ways to support your thyroid and metabolism naturally, be sure to check out my YouTube channel and podcast for more insights.