Iodine

Keep iodine levels in check to ensure steady thyroid hormone production. Deficiency, though uncommon in the U.S., can lead to thyroid enlargement, while excessive iodine intake can worsen hyperthyroidism and hypothyroidism. If you aren’t getting enough through diet (iodine is found in table salt, dairy products, seafood, meat, some bread, eggs, and local produce) be sure it’s in your multivitamin.

Recommended dose: 150 mcg (220 mcg daily for pregnant women, 290 mcg daily for breast-feeding women). Excess iodine can cause or worsen hyperthyroidism and hypothyroidism.

Selenium

A trace mineral that naturally exists in nuts, garlic, shellfish, poultry, eggs, corn, soybeans, and enriched pasta and bread, selenium combines with proteins in the body to form selenoproteins, antioxidants that help regulate thyroid function.

Recommended dose: 55–70 mcg per day

Ashwagandha

Also called Indian ginseng, this adaptogen, or herb that increases the body’s resistance to stress, has been used in Ayurveda for thousands of years to balance thyroid hormones.

Recommended dose: 300–500 mg of a standardized extract daily

Zinc

Necessary for proper function of more than 300 enzymes, this mineral helps the body convert the thyroid hormone thyroxine (T4) to triiodothyronine (T3), an important process for maintaining steady thyroid function.

Recommended dose: 40 mg for low thyroid