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The thyroid is the butterfly-shaped gland at the base of your neck. It produces hormones that regulate your body's energy use, along with many other important functions.
As part of the endocrine system, the thyroid gland helps to regulate the body’s metabolism in the form of blood pressure, blood temperature, and heart rate.
When your thyroid hormone production drops, your body processes slow down and change. Hypothyroidism can affect many different systems in your body.
Common symptoms of hypothyroidism include:
- Fatigue
- Increased sensitivity to cold
- Constipation
- Dry skin
- Weight gain
- Puffy face
- Hoarseness
- Muscle weakness
- Elevated blood cholesterol level
- Muscle aches, tenderness, and stiffness
- Joint pain, stiffness, or swelling
- Heavy or irregular menstrual periods
- Infertility
- Thinning hair
- Slowed heart rate
- Depression
- Impaired memory or brain fog
- Enlarged thyroid gland (goiter)
Undiagnosed thyroid disease puts patients at risk for other ailments, such as cardiovascular diseases, osteoporosis, and infertility.
Hypothyroidism is typically treated with thyroid hormone replacement medication. In addition to thyroid medication, research shows that dietary interventions including supplements may also be supportive to hypothyroid patients.
Specific vitamins and minerals can help your thyroid work optimally. Ideally, most of our essential nutrients should come from our food through a healthy diet. However, some factors can decrease our ability to get nutrients from our food. For example, skipping meals, unhealthy diets, and incorrect food preparation can make it hard to get the vitamins and minerals we need. Thus, people can benefit from taking a dietary supplement, especially if they are the right supplements for their individual needs.
Ahead are the top six vitamins for hypothyroidism (underactive thyroid) to help protect thyroid tissue and encourage thyroid hormone production.
Top six vitamins for hypothyroidism
As one of the most abundant minerals in the human body, and on earth, magnesium plays a critical role in some of our most vital functions including blood pressure, blood glucose metabolism, digestion, muscle and nerve functions, and even helps us sleep. Also, magnesium is responsible for over 300 enzyme reactions involved with protein synthesis. In many ways, magnesium is seen as a cure-all mineral in that it benefits every system in our body.
Magnesium helps improve symptoms often associated with hypothyroidism such as insomnia, fatigue, constipation, high blood pressure, and migraine headaches. Furthermore, magnesium plays an essential role in the conversion of T4 into T3, which can improve thyroid hormone function throughout the body.

Also known as retinol, vitamin A is a fat-soluble organic compound that plays a role in vision, the immune system, reproduction, and cellular communication. One study found that a 4-month trial of vitamin A reduced serum TSH levels in participants. By modulating TSH levels, vitamin A can also support the pituitary gland and prevent enlargement of the thyroid gland. Furthermore, Vitamin A may reduce your risk for autoimmune processes such as Hashimoto’s thyroiditis.

Also called the sunshine vitamin, vitamin D is best known for its critical function in bone health and preventing osteoporosis. This crucial mineral helps the body absorb calcium and phosphorous, which are essential building materials for bone strengthening and repair. People with hypothyroidism often have low vitamin D levels, which may contribute to common symptoms of joint and muscle pain. Low levels of vitamin D may also contribute to leaky gut, which may be a precursor to autoimmune conditions like Hashimoto’s. By increasing vitamin D intake, your digestive system may begin to repair itself. You may even see an improvement in your TSH levels.

Selenium is a trace element that serves as a crucial antioxidant that protects the thyroid gland from oxidative stress. Indeed, one of its primary roles is to regulate the immune system and prevent tissue damage in the thyroid. Because it is a potent immunomodulator, regular intake of selenium supplements has shown to a decrease in TPO antibodies, which, when present, indicates Hashimoto’s. Furthermore, a deficiency in selenium interferes with thyroid hormone metabolism by inhibiting the conversion of T4 to T3.

Best known for its essential purpose in supporting the immune system, zinc is a powerful catalyst for over 100 enzymatic reactions in the body. It is also necessary for protein and DNA synthesis, growth and development, and tissue healing. Our bodies do not have a way to store zinc, so it must be ingested regularly through foods or supplements.
Many people with hypothyroidism have a zinc deficiency, which may be due in part to a damaged digestive system. Zinc supports thyroid hormone production and strengthens the immune system. Furthermore, zinc may help heal leaky gut and decrease overreaction of the immune system as found in allergies and autoimmune conditions.

A deficiency in vitamin B12 is common in many people with hypothyroidism and can also contribute to anemia. Indeed, anemia is found in 20-60% of people with hypothyroidism. People with hypothyroidism and anemia often experience similar symptoms such as fatigue, sluggishness, and cognitive impairment. A B12 supplement can improve hypothyroid symptoms by increasing the number of healthy red blood cells. These cells can deliver oxygen-fresh blood to your tissues and promote energy metabolism.

Safe vitamin consumption
Scientific bodies regularly review and recommend the daily vitamin and mineral intake levels based on age, sex, etc. The U.S. Food and Drug Administration (FDA) developed daily values to help consumers compare the nutrient contents of foods and dietary supplements within the context of a total diet.
Consuming the recommended amount of a vitamin or mineral is safe. Some water-soluble vitamins like riboflavin are even safe at doses several times their recommended levels.
However, high doses of some vitamins or minerals can be dangerous. For example, excessive magnesium can cause diarrhea, zinc can cause nausea and vomiting, and selenium can cause nerve damage or gastrointestinal upset. Some dietary supplements may also interfere with the absorption of your thyroid medication. We recommend you talk with your healthcare provider to optimize your nutrition and treatment.