Q. I’ve been taking levothyroxine for more than a dozen years. I just recently learned I’ve been taking it at the wrong time. I was taking it along with breakfast and coffee, not to mention vitamins, minerals, probiotics, Citrucel and other medications. I am totally confused about how to take it properly.
A. Taking your thyroid medicine with coffee, mineral supplements (especially iron or calcium) or fiber such as bran cereal or Citrucel can interfere with its absorption (Thyroid, March, 2008). Using a calcium-fortified fruit juice to take the medication could severely limit how much gets into your bloodstream. So could a high-calcium food like Greek yogurt. Other foods that may cut absorption of levothyroxine include grapes, soybeans and papaya (European Review for Medical and Pharmacological Sciences, 2014).
Watch Out for Drugs
There are several medications, especially those intended to moderate stomach acid, that can also interfere with proper absorptions. Proton pump inhibitors (esomeprazole, omeprazole, etc.) at high doses may affect absorption. So do antacids taken at the same time as the thyroid pill.
One supplement that you might want to include with your thyroid is vitamin C. In one randomized controlled study, swallowing the pill with water containing 500 mg ascorbic acid dissolved in it improved absorption as determined by lower TSH and higher levels of T4 and T3 (Journal of Clinical Endocrinology and Metabolism, June, 2014).
Switch to Bedtime
Why not take your levothyroxine at bedtime? A small study showed that the drug is absorbed better in the evening (Clinical Endocrinology, Jan., 2007). As long as you don’t eat within two or three hours of retiring, your thyroid medication should work fine and nothing else will interfere with it.
An alternative to that would be Tirosint. This liquid formulation is designed to be absorbed much better, without interference from breakfast beverages such as coffee or a latte (Pharmaceutics, Dec., 2013). You can learn more about thyroid treatment in our Guide to Thyroid Hormones.