Your thyroid gland produces hormones that affect your metabolism, weight, muscle strength, brain development, cholesterol levels and many other body functions. The two main thyroid hormones are triiodothyronine, or T3, and thyroxine, or T4. Another hormone, thyroid-stimulating hormone, or TSH, plays a part in the production of T3 and T4. If you have an underactive thyroid, also known as hypothyroidism, you may experience weight gain, fatigue, pale, dry skin and even depression. Your doctor would likely prescribe you a medication for this condition. Although no scientific, evidence-based thyroid diet exists, you need certain nutrients to maintain thyroid health and hormones.
Iodine and Thyroid Hormones
Iodine is a mineral essential to your thyroid health. Most people in America aren't iodine deficient, because they consume adequate amounts of iodine in the diet. The recommended dietary allowance for iodine is 150 micrograms for adults. The best food sources of iodine are seaweed -- although its iodine content varies -- and other seafood, such as cod and shrimp, as well as dairy, eggs and grains.
Selenium and Your Thyroid
Thought to be essential for thyroid hormone metabolism, selenium is an essential mineral, and the highest concentration is in your thyroid gland. The RDA for selenium is 55 micrograms daily. Food sources of selenium include Brazil and cashew nuts, yellowfin tuna, halibut, chicken, turkey, lentils, whole-wheat bread, oatmeal, eggs and bananas.
Thyroid and Vitamins D and B-12
Studies have linked deficiencies of vitamin D and of vitamin B-12 with thyroid disorders. But more research is necessary to conclude if deficiencies of the vitamin cause the thyroid disorder or if the thyroid disorder causes deficiency. Nonetheless, get your RDA for vitamins D and B-12 to ensure thyroid health. Adults from 19 to 70 need 15 micrograms of vitamin D daily, while adults over 70 need 20 micrograms. Food sources of vitamin D include fatty fish, beef liver, egg yolk, dairy, fortified cereals and mushrooms exposed to ultraviolet light. You can also get vitamin D from sunlight, although the amount varies and depends on several factors. The RDA for vitamin B-12 is 2.4 micrograms daily for people 14 and over. Food sources of B-12 include poultry, fish, eggs and dairy as well as fortified cereals.
Avoid Excess Nutrients
Your doctor can check your thyroid hormones if you have concerns. Also keep in mind that iodine and selenium content in plant foods vary, depending on the levels in the soil where the plant was grown. Always speak with your doctor before taking any vitamin or mineral supplement, because excess consumption of certain nutrients can be detrimental to your health.
- United States Department of Health and Human Services: Thyroid Function Tests
- National Institutes of Health: Hypothyroidism
- Today's Dietitian: Thyroid Disease and Diet — Nutrition Plays a Part in Maintaining Thyroid Health
- My Doctor for Healthy Australia: Thyroid Gland and Thyroid Hormones.
- National Institutes of Health: Iodine -- Fact Sheet for Health Professionals
- National Institutes of Health: Selenium -- Fact Sheet for Health Professionals
- National Institutes of Health: Vitamin B-12 -- Fact Sheet for Health Professionals