iThyroid.com

Following is a list of what I believe are the main causes of hyperthyroidism:

1. Low copper in the diet.
2. High cadmium intake such as from smoking or excessive consumption of green leafy vegetables.
3. High zinc intake for the amount of copper intake.  (Too high a zinc/copper ratio).
4. High iron intake for the amount of copper intake (Too high an iron/copper ratio).
5. High aluminum intake.
6. Low vitamins which metabolize copper.
7. Low minerals which work with copper such as iron and sulfur.
8. Celiac disease or other digestive deficiencies.
9. Progesterone use, including progesterone-based birth control pills.
10. High estrogen levels or estrogen replacement therapy combined with smoking, consumption of excessive green leafy vegetables, or inadequate copper intake.
11.  Lithium, sodium, potassium imbalances.
12. Consumption of canned foods, particularly canned seafood and meats.