Thyroid hormone is used to treat underactive thyroid (hypothyroidism). It is a natural product made from animal thyroid glands (usually a pig's). It replaces or provides more thyroid hormone, which is normally produced by the thyroid gland.
Foods high in potassium include bananas, spinach, carrots and oranges. Decreasing potassium intake can cause levels in the body to drop, but this is not a common reason for a decrease in potassium levels. Low potassium levels can occur when the body loses too much fluid due to illness. This fluid loss may occur because of excessive amounts of vomiting and diarrhea.
If your potassium is below 3.5 mEq/L, you have a condition known as hypokalemia, which means your potassium has dropped to a level that is of medical concern. A potassium level lower than 2.5 mEq/L can be life-threatening, the Mayo Clinic warns.