Supporting thyroid health with vitamins

“Thyros” is the Greek word meaning “shield,”¹ referring to how the thyroid gland resembles a tiny shield, nestled at the base of the throat. The thyroid weighs no more than a couple of AA-sized batteries - approximately 28 grams.²

The battery as a visual metaphor is fitting as the thyroid gland is responsible for producing energy throughout body systems and almost every cell in the body relies on thyroid hormones to function.³

Thyroxine (T4) and triiodothyronine (T3) are the primary hormones synthesised and secreted by the thyroid. Thyroid hormones are essential for regulating key physiological functions, including metabolic rate, energy production, calorie utilisation, and growth and development, particularly during pregnancy and early childhood.⁴

Thyroid hormones also influence the immune response, heart rate, digestion, temperature regulation, and fat metabolism. They also support kidneys, liver, and gallbladder function. When thyroid function is disrupted, it may contribute to changes in mood and emotional wellbeing.⁴

Women seeking to fall pregnant or who are pregnant need to look after their thyroid health as the demands on the thyroid increase dramatically during pregnancy.⁵

Environmental stressors, including chronic stress, poor sleep, exposure to environmental toxins, poor gut health, lack of movement, or even too much movement are potential triggers that can impact thyroid function.⁶

For optimal functioning of the thyroid, specific nutrients are required, including iodine, selenium, iron, zinc and vitamin D.⁷

Iodine is an essential mineral required for the synthesis of thyroid hormones and the maintenance of normal thyroid function. Iodine cannot be produced by the human body; therefore, it must be obtained from external sources^.8 Natural sources of iodine include seawater fish, iodised salt, eggs, yoghurt and commercially manufactured bread (contains iodised salt).⁹

Too much or too little iodine will negatively impact the thyroid, and the presence of an autoimmune disorder (Hashimoto's thyroiditis or Graves’ disease) needs to be identified before supplementing.¹⁰ Being tested by a healthcare professional is recommended to determine individual requirements.¹¹

Selenium is a powerful antioxidant required for the creation, conversion and cellular uptake of thyroid hormones. In adults, the thyroid contains the highest amount of selenium per gram.¹²

Natural sources include Brazil nuts, fish, grains, turkey, chicken, eggs and sunflower seeds.¹³

Excess selenium can lead to toxicity in high doses; therefore, supplementation requires an awareness of appropriate doses.

Iron is required in sufficient quantities to produce thyroid hormones and to facilitate the conversion of T4 to T3 (the active form of the hormone) and for cellular uptake of thyroid hormones.¹⁴

Women who have a menstrual cycle are at increased risk of low iron, and having regular blood tests can help ascertain whether supplementation is required.¹⁵

Natural (animal) sources of iron include meat, chicken and fish. Plant sources include spinach, tofu, lentils, prune juice and cashews.¹⁶

Zinc is required for the production and metabolism of thyroid hormones, the conversion of T4 into the active form of T3 and is also essential for immune system function.¹⁷ Zinc reduces oxidative stress and decreases inflammation.¹⁷

Good sources of zinc include oysters, red meat, turkey, pumpkin seeds, legumes (beans) and nuts.¹⁸

Vitamin D reduces thyroid antibodies by regulating the immune system and improves thyroid function.¹⁹

Dietary sources include oily fish, egg yolks, cod liver oil and meat (especially liver). However, choose grass-fed, organic sources where possible.²⁰

If you are unsure about your thyroid health, speak with your healthcare provider. They can assess your thyroid function and guide you on any next steps to help achieve optimal health and wellbeing.

If you would like to know whether you could benefit from any of the above suggestions, please consult with your health care professional.

Always read the label and follow the directions for use and speak to your healthcare practitioner for more information.