Thyroid Vitamins: What to Know About Supplements for Your Thyroid

The most important nutrient related to thyroid health and function is iodine. The thyroid uses iodine to produce hormones.

Iodine deficiency, which is rare in the United States because of iodized salt, can lead to a condition known as hypothyroidism, which results from the thyroid producing too little hormone.

Hypothyroidism, which leads to low energy and weight gain, among other symptoms, is more common than hyperthyroidism.

Hyperthyroidism occurs when too much thyroid hormone is produced. Too much iodine can trigger hyperthyroidism in some people, so taking iodine supplements is generally not recommended.

In addition to iodine, there are some other vitamins and minerals that you may need to include your regular diet or take as supplements.

• Vitamin A. This vitamin is most often associated with good vision and healthy skin and teeth, but it also plays a role in thyroid hormone metabolism.
• Vitamin D. Research shows that hypothyroidism is often accompanied by vitamin D deficiency. Vitamin D supplements or multivitamins containing vitamin D may be appropriate if your diet doesn't include enough food sources of this important vitamin.
• Selenium. Selenium is an essential mineral that plays several important functions in the body, including the metabolism of thyroid hormones. Maintaining normal levels of selenium in the body is also key to helping to prevent thyroid disease.
• Zinc. A zinc deficiency can adversely affect thyroid function.
• Iron. Sufficient iron levels are also critical to thyroid health. Like selenium and zinc, iron helps the body convert inactive T4 hormone into active T3 hormone.

Some of the best food sources of thyroid vitamins and minerals include many common items found in most Western diets. Such a list should start with foods rich in iodine. Among them are:

• Fish and seafood. Cod, a lean, white fish, and shrimp are excellent sources of protein. Tuna and other types of fish can be good sources of iodine because they naturally retain iodine in seawater.
• Dairy products, such as milk, cheese or yogurt. Stick with low-fat products to avoid the health risks associated with consuming too much saturated fat.
• Egg yolks, which contain most of the iodine found in eggs. Eggs are also good sources of vitamins A and D, as well as selenium.
• Lima beans, which are also good sources of magnesium and fiber.
• Iodized salt. But keep in mind that too much salt (sodium) may lead to higher blood pressure and fluid retention in the body.
• Seaweed is one of the best sources of iodine. Three types of seaweed — kombu kelp, wakame, and nori — are especially good iodine sources.

To get other helpful thyroid vitamins, make sure your diet includes plenty of leafy green vegetables, such as spinach, which is a solid source of vitamin A and iron.

Other good iron food sources include shellfish, red meat, and legumes, which are also packed with selenium.

While most dietitians recommend getting your important nutrients from food rather than supplements, consuming key thyroid vitamins and minerals in pill form may be particularly helpful if your diet doesn't provide those nutrients.

• Selenium. In certain cases, such as autoimmune thyroid disease, supplementation with selenium is helpful. A selenium supplement may be helpful, but don't take more than 200 micrograms (mg) per day, unless otherwise directed by your doctor.
• Zinc. Research also suggests that zinc supplementation may also help maintain healthy thyroid hormone levels.
• Vitamin A. A 2012 study of obese, pre-menopausal women, who are at higher risk for hypothyroidism, found that vitamin A supplementation lowered that risk.

'Thyroid support' supplements

In addition to traditional multivitamins or single-item vitamins and supplements, you may see products claiming to be ideal for 'thyroid support' or 'thyroid strength.'

These thyroid vitamin and mineral supplements may be convenient ways to get enough key nutrients. But many of them also come with herbal supplements, such as ashwaganda.

Be mindful that while some herbal supplements may be safe and actually provide health benefits, supplements are not tested by the Food and Drug Administration (FDA) or reviewed with the same level of scrutiny as medications.

They may contain ingredients not listed on the label, and it's not always clear how much of a particular ingredient is contained in each pill.

Many 'thyroid support' products also contain synthetic thyroid hormone, which can lead to an imbalance of hormone levels in your body, whether or not you're taking prescription synthetic hormones.

It's very important that you speak with your healthcare provider before taking a 'thyroid support' supplement or any supplements or vitamins.

For people with hypothyroidism, taking a synthetic version of the hormone in pill form can help them achieve healthy hormone levels. However, there are some foods, medications and other supplements that should be avoided when taking your thyroid hormone. Among them are:

• iron supplements or multivitamins containing iron
• calcium supplements
• antacids that contain magnesium or aluminum
• sucralfate (Carafate) and certain other ulcer medications
• certain cholesterol-lowering drugs, including those that contain cholestyramine (Prevalite) and colestipol (Colestid)
• soybean flour
• cottonseed meal
• walnuts
• foods and supplements containing soy

You may still be able to consume these items, but you should take them a few hours before or after taking your thyroid medication. Talk with your doctor about a daily schedule that will help reduce your risk of unhealthy interactions.

Eating a healthy, well-rounded diet is usually enough to provide the necessary nutrients for a healthy thyroid and overall physical health.

Remember to make sure you get enough iodine in your diet, as well as some other key vitamins and minerals, such as vitamins A and D, as well as zinc, magnesium and selenium.

Be wary of products sold as 'thyroid vitamins,' especially if they contain herbal supplements or even small amounts of thyroid hormones.

A standard physical should include an exam of your thyroid to check for changes in size or shape. If you notice a change or you start to experience symptoms of hyperthyroidism or hypothyroidism, see a doctor soon.

A blood test to check for thyroid hormone levels can help confirm hyperthyroidism, hypothyroidism, or that your levels are in a healthy range.