There's no need to follow a special diet when you have an overactive thyroid, or hyperthyroidism. While thyroid hormones play a role in your nutritional health -- by assisting in the metabolism of carbohydrates, fats and proteins -- what you eat or don't eat does not alter the course of the illness. As such, there are no "best foods" that help manage an overactive thyroid. Due to the effects excess thyroid hormones might have on your bones, however, you might benefit from upping your intake of vitamin-D-rich foods if you have hyperthyroidism.
Hyperthyroidism and Vitamin D
Your bones are in a continual state of turnover, as old bone is broken down and replaced with new bone. Untreated hyperthyroidism increases bone turnover, such that bone breakdown outpaces the deposition of new bone. This imbalance decreases bone strength and increases risk of fractures. Excess thyroid hormone also alters vitamin D metabolism, and low levels are common in people with untreated hyperthyroidism. Once the disease is treated and thyroid hormone levels return to normal, your bones work to recover. Because vitamin D is an important nutrient for bone health, your doctor may recommend you increase your intake of foods rich in this vitamin, such as vitamin-D-fortified milk or fatty fish like salmon.
When to See Your Doctor
Prompt treatment of hyperthyroidism reduces the risk of complications, including loss of bone strength. So it's important to see your doctor if you experience symptoms that may signal an overactive thyroid, such as mood swings, restlessness, weakness, increased appetite, unintentional weight loss or feeling hot all the time. Seek emergency medical care if you've had symptoms of possible hyperthyroidism and suddenly develop a high fever, profuse sweating, nausea, vomiting, abdominal pain or confusion. These symptoms may indicate a condition called a thyroid storm, with extremely high levels of thyroid hormones. The condition is potentially life-threatening if not treated immediately.