Watch What You Eat
The foods you eat and medicines you take can have a big effect on how well your body absorbs your thyroid medication. Ideally, you should take your pill on an empty stomach since food can delay absorption.
It's best to wait an hour after you take your pill before eating. But if you need to eat something before taking your thyroid drug, do that every day, and discuss it with your doctor. The key is to be consistent. Varying it will make absorption erratic and cause hormone levels to be irregular.
Certain foods and supplements can inhibit your body's absorption of thyroid medications, too. A diet rich in fiber, for example, may decrease the amount of thyroid medication that your body absorbs.
If you're already eating a high-fiber diet at the time you start taking thyroid replacement, your body will settle into the proper dosage with the fiber taken into account. But if you decide to start eating a high-fiber diet after starting your thyroid drug, be sure to let your doctor know. You may need a higher dose of thyroid medication.
Some experts believe that certain foods, eaten raw, can promote thyroid problems by blocking the thyroid's uptake of iodine. These foods are known as goitrogens and include items such as broccoli, cabbage, kale, cauliflower, Brussels sprouts, and turnips. In reality, however, most goitrogens do not cause thyroid problems unless eaten in large quantities.
In addition, some substances and minerals in food can inhibit absorption of thyroid medications. These substances should not be ingested at the same time you take your thyroid drug. Foods and supplements that inhibit absorption include:
Calcium supplements and calcium-fortified foods
Soy foods and other foods that contain isoflavones
Antacids that contain either calcium or aluminum hydroxide
Taking calcium or iron is especially problematic. If you must eat these foods or take these supplements, make sure to wait at least one hour after taking your thyroid medication before doing so. Spacing them out will reduce the likelihood that these foods and supplements will affect your thyroid treatment.