The 5 Best Thyroid Supplements of 2024, According to Dietitians
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According to the American Thyroid Association, roughly 20 million Americans have a thyroid disease. If you’re in this category, you may be curious about which dietary supplements could be most helpful for your overall health and your thyroid function.
Here are the best thyroid support supplements according to dietitians, along with a guide to choosing the best thyroid supplement for your specific needs.
This content is meant to be informative, but should not be taken as medical advice. It is not intended for use as diagnosis, prevention or treatment of health problems. Always speak with your doctor before starting any new supplement or exercise regimen.
Our Picks for Best Thyroid Supplements:
- Best Vitamin D: Transparent Labs Vitamin D3
- Best Zinc: Naked Nutrition Immune Support Supplement
- Best Iron: Thorne Iron Bisglycinate
- Best Selenium: Pure Encapsulations Selenium
- Best Omega-3 Fatty Acids: Transparent Labs Krill Oil
Best Vitamin D: Transparent Labs Vitamin D3
Transparent Labs
Key features & specs
- Key ingredients: Vitamin D3, vitamin K2
- How it supports thyroid function: Supports production of thyroid hormones
- Vitamin D per serving: 5,000 IU (630% of the Daily Value [DV])
- Certifications: Third-party tested by Analytical Resource Labs
- Subscription: Choose frequency, 10% off
- Price per serving: $0.17
Kelly Springer, MS, RD, CDN, dietitian and founder of nutritional consulting company Kelly’s Choice, says, “I would argue that vitamin D supplementation is beneficial for most individuals.” She explains that vitamin D is synthesized from sun exposure, which many people don’t get enough of. “Deficiency has been linked to chronic illnesses, including autoimmune diseases like thyroid disease,” she says, adding that people who take a vitamin D supplement have been shown to have better thyroid hormone production and reduced inflammation.
This supplement from Transparent Labs also contains vitamin K2, which works with vitamin D to support bone health. Additionally, Transparent Labs makes supplements that are third-party tested and free of artificial colors, sweeteners and flavors. However, it does contain the additive titanium dioxide, which some users may prefer to avoid.
This product is highly rated by reviewers, both for quality and customer experience. It has 4.7/5 stars and 53 reviews at the time of writing.
"I've been using the 2x 5000iu D3 supplement daily for a few years now, ever since being diagnosed with low testosterone," says Christopher, a reviewer on the Transparent Labs website. "Along with my hormone therapy, I feel this supplement is one of the reasons I'm so rarely sick now, and have more energy on a regular basis."
What we love:
- Contains both vitamin D and vitamin K2, which work together
- Third-party tested
- Highly-rated by reviewers
What to consider:
- Contains the additive titanium dioxide
Best Zinc: Naked Nutrition Immune Support Supplement
Naked Nutrition
Key features & specs
- Key ingredients: Vitamin A, vitamin C, vitamin D3, zinc, selenium, beta-glucan, ParActin, ivy leaf extract, organic Reishi mushroom
- How it supports thyroid function: Necessary for thyroid hormone production
- Zinc per serving: 30 milligrams (270 percent DV)
- Certifications: Non-GMO
- Subscription: Choose frequency, 20% off first order and 10% off recurring orders
- Price per serving: $1.25
Zinc is a key nutrient for thyroid health, according to Springer, and assists with the function of numerous other hormones and enzymes. She says, “Zinc specifically works with selenium to synthesize thyroid hormones.”
This immune system support blend from Naked Nutrition contains 270 percent of the DV for zinc, in addition to other nutrients that may support thyroid health, like vitamin C. “Vitamin C acts as an antioxidant that neutralizes free radicals in the body,” Springer says.
There are limited reviews online for this product (only seven at the time of writing), but they are mostly positive. One reviewer on the Naked Nutrition website named Jillian Doing says, "Whenever I felt like a cold coming, itch in throat, runny nose, sore to swallow... I took 3 of these and felt better the next day. I'd take 1 the next day to seal the deal, as instructed. And symptoms would be gone. Going to always have a bottle of these in the house! They're on the larger side, but still easy for me to swallow. No weird taste, but honestly even if there was it would be worth it."
Related Post: The Best Vitamins and Supplements to Boost Your Immune System
What we love:
- Contains zinc and other immune support nutrients
- GMO-free
- Subscription discount available
What to consider:
- Expensive
- Three pills per serving
Best Iron: Thorne Iron Bisglycinate
iHerb
Key features & specs
- Key ingredients: Iron
- How it supports thyroid function: Thyroid hormone synthesis
- Iron per serving: 25 milligrams (139 percent of the DV)
- Certifications: N/A
- Subscription: N/A
- Price per serving: $0.23
“Iron aids in hormone synthesis,” explains Springer. “If you have a deficiency in this mineral, hormone synthesis will be impaired.” Supplementation may be particularly important if you’re following a plant-based diet, since heme iron from animal sources is absorbed significantly better than non-heme iron from plant sources.
This supplement from Thorne contains iron bisglycinate, a form that may be particularly helpful for people with iron deficiency anemia. It’s also highly rated by reviewers, and they say it doesn’t upset their stomachs like other iron supplements.
An Amazon customer named Miriam T. says, "I've tried other iron supplements that have resulted in constipation and upset stomach. However, I don't get any of the negative symptoms when taking this." The main complaint about this supplement is the inclusion of silicon dioxide as an anti-caking agent, though it's considered safe for use in supplements in the U.S.
What we love:
- Contains iron bisglycinate, which is tolerated better than other forms of iron
- Shouldn't cause intestinal problems (nausea, diarrhea or cramping) like other forms of iron
- Highly rated (only 4/5- and 5/5-star reviews)
What to consider:
- Contains the additive silicon dioxide
Best Selenium: Pure Encapsulations Selenium
Amazon
Key features & specs
- Key ingredients: Selenium
- How it supports thyroid function: Antioxidant, activates thyroid hormones
- Selenium per serving: 200 micrograms (mcg) (364 percent of the DV)
- Certifications: Certified Gluten-Free, non-GMO, vegan
- Subscription: N/A
- Price per serving: $0.22
“Selenium is an essential factor in thyroid health,” says Springer. This trace mineral activates thyroid hormones and has antioxidant activity, she explains. She also recommends selenium supplementation for people with thyroid dysfunction.
Pure Encapsulations is well-known for making high-quality, allergen-free dietary supplements that are designed for maximal absorption. Their selenium supplement provides 364 percent of the DV for selenium per serving.
Although Pure Encapsulations vitamins can be more expensive than others, this brand is highly recommended by practitioners, and some reviewers even comment that their thyroid health has improved since starting this supplement.
What we love:
- Reputable vitamin brand
- Provides over 350 percent of the DV for selenium
- Highly rated by customers
What to consider:
- More expensive than other brands
Best Omega-3 Fatty Acids: Transparent Labs Krill Oil
Transparent Labs
Key features & specs
- Key ingredients: Krill oil
- How it supports thyroid function: Reducing inflammation
- Omega-3 per serving: 220 milligrams
- Certifications: Third party testing by Analytical Resource Labs
- Subscription: Choose frequency, 10% discount
- Price per serving: $1.17
According to Springer, people with thyroid disorders need at least two servings of fish per week for omega-3 fatty acids—much like everyone else. However, she says, “Supplementation may be beneficial for impaired digestion due to thyroid disease.” She adds that the anti-inflammatory properties of krill oil may help reduce inflammation in the thyroid glands, which can help slow the progression of symptoms.
This pure krill oil supplement from Transparent Labs contains 1,000 milligrams of Superba Krill Oil, which provides a total of 220 milligrams of omega-3 fatty acids. Although this supplement is more expensive than many fish oils, reviewers say they like it because krill oil doesn’t have the same fishy aftertaste. Also, krill oil may also be easier to absorb than fish oil.
What we love:
- Third-party tested
- May be easier to absorb than fish oil
- Anti-inflammatory properties
What to consider:
- More expensive than fish oil
Who May Benefit From a Thyroid Supplement?
The nutrients we listed above—omega-3 fatty acids, selenium, iron, vitamin D, zinc and magnesium—may all help promote healthy thyroid function.
However, that doesn’t necessarily mean you need to take all of these supplements if you have a thyroid condition.
“I encourage you to increase your intake of foods high in these vitamins and minerals,” says Springer. That includes a wide variety of whole foods, including meat, fish, fruits, vegetables, whole grains, nuts and seeds.
She also adds, “If you’re having trouble meeting the requirements for consumption, supplementation will be beneficial.”
If you’re experiencing any symptoms that could be related to a nutrient deficiency—like low energy levels, brain fog, thinning hair, brittle nails or digestive issues—she recommends have your blood levels tested. “If your blood levels of vitamins and minerals are low,” she says, “then you should supplement with those vitamins or minerals.”
Related Post: Best At-Home Thyroid Tests
Potential Risks
There are some risks to thyroid supplements, as well as other dietary supplements.
It’s important to understand how your supplements may interact with any medications you’re taking. Your doctor or pharmacist can help you determine if there are any potential interactions between your medications and your supplements.
Springer says, “There is an upper limit to vitamin and mineral consumption, and over-supplementation can lead to toxicity.” She is referring to the Tolerable Upper Intake Level (UL), an amount of any nutrient that may cause adverse effects if you exceed it in one day. With supplements that deliver extremely high doses of nutrients, it can be surprisingly easy to exceed the UL—especially if you’re also taking multivitamins or supplement blends that contain high concentrations of the same nutrient.
She also urges caution with supplementation in pregnant women. “They can see significant changes in their hormone levels,” she says, “including thyroid hormones.”
“Supplementation may be beneficial,” she concludes, “but speaking to your medical provider before starting is essential.”
How to Choose the Best Thyroid Supplement for You
Here are some factors to consider when choosing thyroid supplements.
Third-party approval
“Supplements don’t have to be approved by the Food & Drug Administration (FDA) before being placed on the shelf,” says Springer. This means that some supplements may not actually contain what the label says they contain.
However, she adds, “Having a third-party approved stamp on the supplement assures the customer that they are provided with the nutrients listed on the bottle, and no harmful elements. The third-party stamp marks the supplement as safe and effective.”
Some of the most common third-party certification agencies you’ll see on supplement labels include United States Pharmacopeia (USP), NSF and Informed Choice. Many brands also pursue third-party testing from smaller labs. You can usually find details about third-party testing, methods and laboratories used on the brand’s website.
High quality ingredients
Ingredient quality is another important consideration. In many cases, fillers and other artificial, industrial ingredients—like sweeteners, colors and flavors—simply aren’t necessary. “Avoid supplements with fillers,” cautions Springer.
She also recommends seeking out non-GMO and organic products. “These labels guarantee the product contains natural ingredients,” she says.
Careful dosing
Look for supplements that don’t contain extremely high doses of any nutrients. If you’re concerned, look up the UL for the nutrient and compare it to the amount of that nutrient in one serving of the supplement you’re researching. “There is an upper limit for a reason,” Springer says.
It’s particularly important to do this with fat-soluble vitamins (vitamins A, D, E and K). Excess amounts of these vitamins are stored in your body’s fat cells, while excess amounts of many other nutrients are simply flushed out in your urine, sweat or bowel movements. For this reason, fat-soluble vitamin toxicity can occur more easily than some other nutrient toxicities.
Professional input
Especially with thyroid disease, it’s important to speak to your doctor or dietitian before adding new supplements to your routine. “Individuals with a thyroid condition may have other conditions where a supplement may or may not be recommended,” says Springer.
They may also be able to provide recommendations for the best supplements to take for you specifically, or order the blood tests you need to see if you have any nutrient deficiencies that need to be addressed.
When to See a Doctor
Wondering if you need to see a doctor for your thyroid? According to Springer, there are a few signs and symptoms that warrant making an appointment with your healthcare provider.
“There are two forms of thyroid disease,” she explains. “Hyperthyroidism and hypothyroidism. Hyperthyroidism occurs when your thyroid gland is producing too much thyroid hormone,” she says. According to Springer, potential symptoms of hyperthyroidism include:
- Anxiety
- Fatigue
- Frequent bowel movements
- Hair loss
- Increased appetite
- Increased sweating
- Nail changes
- Racing heartbeat
- Sleeping problems
- Weight loss
On the other hand, she says, “Hypothyroidism occurs when your body is not producing enough thyroid hormones.” She cites the following as potential symptoms of hypothyroidism:
- Fatigue
- Weight gain
- Joint and muscle pain
- Dry skin
- Irregular menstrual periods
- Slow heart rate
- Depression
- Brittle nails
- Hair loss
- Constipation
“If you are having some of these symptoms,” she says, “talk to a medical provider. Blood tests may be beneficial to see what is happening inside your body.” Some of the blood levels your provider may check when assessing your thyroid health include thyroid stimulating hormone (TSH), thyroxine (T4), triiodothyronine (T3) and thyroid antibodies.
How We Chose the Best Thyroid Supplements
We considered a number of criteria when choosing the best thyroid health supplements. First, we made sure that the key ingredients in these supplements were actually helpful for thyroid health. Then, we considered ingredient quality and absorbability. We also sought out brands that are reputable and trustworthy, many of which pursue third-party testing or certifications for their products.
Thyroid Supplement FAQs
How do you tell if your thyroid is off?
According to Springer, thyroid problems can manifest from a variety of non-specific symptoms—like fatigue, weight gain and constipation. The best way to know for sure is to visit your healthcare provider and see if they can check your thyroid hormone levels.
Do thyroid supplements really help?
Yes, if you aren’t getting enough of certain nutrients that support thyroid health in your diet, or if you have any nutrient deficiencies, supplementing with these specific nutrients can help.
How can I boost my thyroid function naturally?
This depends on whether you’re experiencing hypothyroidism or hyperthyroidism. Your healthcare provider can help you figure this out. However, getting enough sleep, managing stress, eating a healthy and balanced diet and engaging in regular exercise are good lifestyle choices that can help optimize your health in a variety of ways.
What supplements should I avoid if I have thyroid problems?
“I suggest you wait four hours after taking thyroid medication before you take any vitamin or mineral supplements,” says Springer. She explains that some supplements, like calcium and iron, can interfere with medication absorption. Additionally, she adds that you should stop taking biotin supplements a few days before having bloodwork done because biotin can falsely change the results of thyroid blood tests.
Takeaway: Is Taking a Thyroid Supplement Worth It?
If you have thyroid issues like hypothyroid or hyperthyroid, certain supplements may be beneficial for you for thyroid support and overall health. These include iron, vitamin D, magnesium, zinc, selenium and omega-3 fatty acids.
However, the best way to know which supplements you need is to ask your doctor for a blood test. This will reveal if you are dealing with any nutrient deficiencies so that you can confidently correct them through supplements and diet changes.
If you have a thyroid condition, it’s very important to consult your healthcare provider before adding any new supplements to your routine.
Prices are accurate and items in stock as of publish time.
