Skip to main content
The Globe and Mail
Support Quality Journalism
The Globe and Mail
First Access to Latest
Investment News
Collection of curated
e-books and guides
Inform your decisions via
Globe Investor Tools
per week
for first 24 weeks

Enjoy unlimited digital access
Enjoy Unlimited Digital Access
Get full access to
Just $1.99 per week for the first 24 weeks
Just $1.99 per week for the first 24 weeks
var select={root:".js-sub-pencil",control:".js-sub-pencil-control",open:"o-sub-pencil--open",closed:"o-sub-pencil--closed"},dom={},allowExpand=!0;function pencilInit(o){var e=arguments.length>1&&void 0!==arguments[1]&&arguments[1];select.root=o,dom.root=document.querySelector(select.root),dom.root&&(dom.control=document.querySelector(select.control),dom.control.addEventListener("click",onToggleClicked),setPanelState(e),window.addEventListener("scroll",onWindowScroll),dom.root.removeAttribute("hidden"))}function isPanelOpen(){return dom.root.classList.contains(}function setPanelState(o){dom.root.classList[o?"add":"remove"](,dom.root.classList[o?"remove":"add"](select.closed),dom.control.setAttribute("aria-expanded",o)}function onToggleClicked(){var l=!isPanelOpen();setPanelState(l)}function onWindowScroll(){window.requestAnimationFrame(function() {var l=isPanelOpen(),n=0===(document.body.scrollTop||document.documentElement.scrollTop);n||l||!allowExpand?n&&l&&(allowExpand=!0,setPanelState(!1)):(allowExpand=!1,setPanelState(!0))});}pencilInit(".js-sub-pencil",!1); // via darwin-bg var slideIndex = 0; carousel(); function carousel() { var i; var x = document.getElementsByClassName("subs_valueprop"); for (i = 0; i < x.length; i++) { x[i].style.display = "none"; } slideIndex++; if (slideIndex> x.length) { slideIndex = 1; } x[slideIndex - 1].style.display = "block"; setTimeout(carousel, 2500); }

Q: I’ve been diagnosed with low thyroid and have started taking medication. Are there certain foods that I can eat to help my thyroid? Any foods that I should avoid?

Low on iron? Add these foods to your diet

New study adds evidence to link between nutrition and breast cancer risk

Are natural sugar substitutes better than white sugar?

Your thyroid gland relies on several nutrients to function properly. Minerals such as iodine and selenium, for example, are essential for making thyroid hormones.

While good nutrition is important for thyroid health, diet and supplements are not a replacement for thyroid medication. And if you have hypothyroidism (low thyroid), there are some foods and supplements that you need to be cautious about.

Story continues below advertisement

Low thyroid 101

The thyroid gland, located at the front of the neck, makes and stores thyroid hormones which affect nearly every organ in the body. Called triiodothyronine (T3) and thyroxine (T4), thyroid hormones regulate the speed of your metabolism, body temperature, cell growth, brain development, cholesterol levels, blood calcium levels and much more.

When the thyroid gland doesn’t produce enough thyroid hormones, hypothyroidism results. Symptoms include unexplained weight gain, constipation, fatigue, hair loss, dry skin, intolerance to cold, difficulty concentrating, joint pain and menstrual-cycle changes.

People of any age can develop hypothyroidism, but older adults are more likely to get it, especially older women. If the condition runs in your family, you also have a higher risk.

In Canada, the most common cause of hypothyroidism is Hashimoto’s thyroiditis, an autoimmune disorder in which the body’s immune system attacks the thyroid gland reducing its ability to make thyroid hormones.

Once the body can no longer produce an adequate amount of thyroid hormones to support its functioning, thyroid replacement medication is necessary.

Nutrition for thyroid function

Iodine, a mineral found in iodized table salt, fish and seafood, dairy products, grains and seaweed, is an essential component of thyroid hormones. People who don’t consume enough iodine are at risk for developing hypothyroidism.

Adults need 150 mcg of iodine each day for normal thyroid function. Pregnant women require 220 mcg daily and are advised to take a multivitamin and mineral supplement containing 150 mcg of the mineral to ensure proper development of a baby’s brain and nervous system.

Story continues below advertisement

Getting too much iodine can also harm thyroid function. Avoid consuming excess iodine (e.g. supplements, seaweed products), which can worsen hypothyroidism.

Selenium is a vital component of enzymes involved in the synthesis of thyroid hormones. The mineral also acts as an antioxidant, protecting thyroid tissue from harmful free radical molecules.

The daily recommended intake of selenium is 55 mcg for women and men. Excellent sources include Brazil nuts (1 nut has 95 mcg), tuna, halibut, sardines, shrimp, beef, turkey, cottage cheese, brown rice and eggs.

Consuming too much selenium can be toxic; the safe upper limit from foods and supplements is 400 mcg a day.

Zinc also plays a role in making thyroid hormones. It’s found in oysters, beef, crab, pork, chicken, pumpkin seeds, cashews, chickpeas, yogurt, milk and fortified breakfast cereals.

Foods that may disrupt the thyroid

Naturally occurring compounds in some foods are considered goitrogens, which means they can interfere with the production of thyroid hormones.

Story continues below advertisement

Compounds in cruciferous vegetables (e.g. bok choy, broccoli, Brussels sprouts, cauliflower, cabbage, collard greens, kale, turnip) called thiocyanates, for example, can reduce the uptake of iodine in the thyroid. Eating too much of these vegetables is considered only a concern for people who have an iodine and/or selenium deficiency, which is uncommon in North America.

Still, if you have an underactive thyroid, it’s wise to avoid juicing cruciferous vegetables since it concentrates the amount of goitrogens. Cooking cruciferous vegetables, even lightly steaming them, deactivates goitrogens.

Isoflavones in soy foods such as tofu, soy milk, edamame and miso can also reduce thyroid hormone synthesis. But, again, studies have found that this does not affect people with adequate iodine stores.

Studies in the 1980s found that pearl millet, a gluten-free grain, was goitrogenic, even in people who were not iodine deficient. Much of the millet sold in North American is proso millet, which has not been shown to be goitrogenic.

If millet and millet products are your staple grain products, call the manufacturer to find out which type of millet is used.

Time supplements around medication

Calcium, iron and chromium supplements interfere with the proper absorption of thyroid replacement medication. So can antacids that contain calcium, magnesium and aluminum.

Story continues below advertisement

Space these products four hours apart from thyroid medication.

Fibre supplements may reduce the absorption of thyroid medication; it’s best to take them one hour apart.

If you’re unsure about other supplements or medications that my interfere with your thyroid medication, speak to your pharmacist.

Leslie Beck, a Toronto-based private practice dietitian, is Director of Food and Nutrition at Medcan.

Live your best. We have a daily Life & Arts newsletter, providing you with our latest stories on health, travel, food and culture. Sign up today.

Related topics

Report an error Editorial code of conduct
Due to technical reasons, we have temporarily removed commenting from our articles. We hope to have this fixed soon. Thank you for your patience. If you are looking to give feedback on our new site, please send it along to If you want to write a letter to the editor, please forward to

Welcome to The Globe and Mail’s comment community. This is a space where subscribers can engage with each other and Globe staff. Non-subscribers can read and sort comments but will not be able to engage with them in any way. Click here to subscribe.

If you would like to write a letter to the editor, please forward it to Readers can also interact with The Globe on Facebook and Twitter .

Welcome to The Globe and Mail’s comment community. This is a space where subscribers can engage with each other and Globe staff. Non-subscribers can read and sort comments but will not be able to engage with them in any way. Click here to subscribe.

If you would like to write a letter to the editor, please forward it to Readers can also interact with The Globe on Facebook and Twitter .

Welcome to The Globe and Mail’s comment community. This is a space where subscribers can engage with each other and Globe staff.

We aim to create a safe and valuable space for discussion and debate. That means:

  • Treat others as you wish to be treated
  • Criticize ideas, not people
  • Stay on topic
  • Avoid the use of toxic and offensive language
  • Flag bad behaviour

Comments that violate our community guidelines will be removed.

Read our community guidelines here

Discussion loading ...

To view this site properly, enable cookies in your browser. Read our privacy policy to learn more.
How to enable cookies