Hypothyroidism, also known as underactive thyroid, is a common condition where the thyroid gland does not produce enough thyroid hormones. This can lead to a variety of symptoms like fatigue, weight gain, dry skin, hair loss, and feeling cold. Hypothyroidism is typically treated with medication, but some alternative therapies like zinc supplements have been suggested to help manage symptoms.
What causes hypothyroidism?
The most common cause of hypothyroidism is Hashimoto’s thyroiditis, an autoimmune disease where the immune system mistakenly attacks the thyroid gland, damaging it and reducing hormone production. Other potential causes include:
- Thyroid surgery
- Radiation treatment to the thyroid
- Some medications
- Too much or too little iodine intake
- Congenital (present from birth) hypothyroidism
- Pituitary gland disorders
What are the symptoms of hypothyroidism?
Symptoms of hypothyroidism can vary from person to person, but may include:
- Fatigue
- Weight gain or difficulty losing weight
- Dry, thinning hair
- Dry, rough pale skin
- Feeling cold
- Muscle weakness
- Elevated blood cholesterol
- Muscle cramps and joint pain
- Constipation
- Depression
- Impaired memory
- Abnormal menstrual cycles
- Slowed heart rate
Symptoms tend to develop gradually over months and years. Not everyone with hypothyroidism experiences all potential symptoms.
How is hypothyroidism diagnosed?
Diagnosing hypothyroidism involves blood tests measuring levels of thyroid stimulating hormone (TSH) and thyroid hormones T3 and T4. Typical findings include:
- High TSH levels
- Low free T4 levels
- Low or normal free T3 levels
Other supplemental tests may check for antithyroid antibodies to help diagnose Hashimoto’s thyroiditis. Doctors may also examine the thyroid gland for enlargement or nodules.
How is hypothyroidism treated conventionally?
The standard treatment for hypothyroidism is daily oral medication with synthetic thyroid hormone levothyroxine (Levoxyl, Synthroid, Tirosint, Unithroid). This replaces the thyroid hormone the body is unable to produce itself. Typical starting dose is 1.6 mcg per kg of body weight. The dose is then adjusted based on follow up lab work and symptom improvement.
It may take 4-6 weeks after starting medication to see improvement in hypothyroidism symptoms. Thyroid hormone replacement is generally required lifelong. Regular monitoring of TSH levels through blood tests helps determine the proper maintenance dosage over time.
What is the role of zinc in thyroid function?
Zinc is an essential mineral that plays many important roles in the body and thyroid function. Specifically, zinc is critical for:
- Synthesis, secretion, and metabolism of thyroid hormones
- Regulating TSH production
- Converting T4 to active T3 thyroid hormone
- Structural integrity of thyroid gland
Zinc deficiency may potentially lead to hypothyroidism symptoms due to inadequate thyroid hormone production and metabolism.
Zinc rich foods
The recommended daily intake of zinc is 8-11 mg for adults. Good dietary sources of zinc include:
| Food | Serving | Zinc (mg) |
|---|---|---|
| Oysters | 6 medium | 76.3 |
| Beef | 3 ounces cooked | 7.0 |
| Crab | 3 ounces cooked | 6.5 |
| Lobster | 3 ounces cooked | 3.4 |
| Yogurt | 1 cup | 1.7 |
| Chickpeas | 1 cup cooked | 2.5 |
| Cashews | 1 ounce | 1.6 |
| Almonds | 1 ounce | 0.9 |
Can zinc supplementation help hypothyroidism?
Some research indicates that supplementing with zinc may help manage hypothyroidism symptoms, particularly in those with zinc deficiency. Potential benefits include:
- Improving thyroid hormone levels – Studies show zinc supplementation can increase circulating T3 and T4 hormones in those with low zinc status.
- Lowering TSH – Multiple studies found zinc supplementation helps lower elevated TSH levels, improving thyroid function.
- Enhancing conversion of T4 to T3 – Zinc is essential for the enzymes that convert inactive T4 to active T3 thyroid hormone.
- Reducing antithyroid antibodies – In Hashimoto’s patients, zinc may lower levels of antibodies attacking the thyroid.
- Improving thyroid symptoms – Some studies show zinc supplementation improves fatigue, weight, hair loss, and mood issues in hypothyroid patients.
However, there are some inconsistencies in research results. Not all studies demonstrate a clear benefit of zinc for hypothyroidism. More research is still needed.
Key studies on zinc and hypothyroidism
Here is a summary of key scientific studies investigating the effects of zinc supplementation on hypothyroidism:
| Study | Participants | Zinc dose | Length | Results |
|---|---|---|---|---|
| Nacak et al 2011 | 30 women with hypothyroidism | 50 mg zinc gluconate daily | 3 months | Lowered TSH and anti-thyroid antibodies. Increased T3 and T4. |
| Jamilian et al 2018 | 64 women with hypothyroidism | 30 mg zinc gluconate daily | 8 weeks | Lowered TSH. Improved symptoms. |
| Solomon et al 2017 | 44 adults with hypothyroidism | 30 mg zinc gluconate twice daily | 12 weeks | Lowered TSH. Increased T3 and T4. |
| Fazeli et al 2020 | 64 women with hypothyroidism | 30 mg zinc sulfate daily | 8 weeks | No improvement in TSH or thyroid hormones. |
Are there risks or side effects of too much zinc?
High doses of zinc from supplements long-term can potentially lead to side effects including:
- Nausea
- Vomiting
- Diarrhea
- Metallic taste
- Copper deficiency
- Neurological issues
- Kidney problems
Excessive zinc intake can interfere with absorption of other minerals like iron and calcium as well. The tolerable upper limit (TUL) of zinc is 40 mg per day for adults. This is the maximum amount considered safe from food and supplements combined.
For hypothyroidism, aim to get zinc from food sources first whenever possible. Supplement doses for hypothyroidism typically range from 30-60 mg elemental zinc per day.
Conclusion
Research to date suggests zinc may potentially help support thyroid function and relieve symptoms in some hypothyroid patients, particularly those with zinc deficiency or Hashimoto’s disease. However, the benefits are not consistent across all studies so more research is still needed.
When used appropriately, zinc supplementation appears relatively safe for most people and may help boost thyroid hormone levels and lower TSH. However, excessive zinc intake can produce side effects so recommended upper limits should be respected.
For managing hypothyroidism, ensure adequate zinc intake through foods first and use supplements cautiously under medical supervision. Zinc may provide added support but should not replace standard thyroid hormone medication prescribed by a doctor.