Thyroid-disrupting mineral deficit that 75% of doctors miss

Selenium shortfalls are a common

cause of thyroid imbalances, says Ken Berry, M.D., author of Lies My Doctor Told Me. “Selenium is absolutely necessary for healthy thyroid function—the active form of thyroid hormone can’t be produced in proper amounts unless selenium levels are adequate.” Indeed, in a study in The Journal of Clinical Endocrinology & Metabolism, people with low selenium were 69% more likely to have low thyroid function. And since selenium is crucial for healthy immune function, deficits can trigger a misguided response that causes the immune system to attack the gland, leading to energy-draining imbalances.

Adding to the problem: The NIH says selenium deficiency is rare in the U.S. But modern farming depletes selenium in soil and crops grown in it. And research finds diets high in processed foods increase the risk of shortfalls by 97%.

Doctors can diagnose selenium deficits and the thyroid imbalances they trigger with blood tests. And while doctors often prescribe thyroid medication, the strategies below can also help.

Supplementing with selenium

can optimize thyroid function, say researchers in Italy. Sanul Corrielus, M.D., CEO of Corrielus Cardiology in Philadelphia, advises taking 100 to

200 mcg. daily of a product that contains selenomethionine, an easily absorbed form of the mineral. One to try: Swanson Premium Selenium L-Selenomethionine 100 mcg., Walmart.com. Note: Too much selenium can cause nausea, hair loss and other toxicity symptoms, so talk to your doctor before supplementing.

Also key: Eat selenium-rich foods.

Dr. Berry advises options like beef, poultry, fish and eggs daily. Tip: Two Brazil nuts boast 192 mcg. of selenium, so skip supplements on days you eat them to avoid selenium overload.