Thyroxine is a hormone produced by the thyroid gland that is needed for metabolic functions in the body. Levothyroxine is a synthetic form designed to replace thyroxine in people with certain thyroid conditions. Calcium with vitamin D can affect levothyroxine absorption when taken at the same time. Consult your physician for specific recommendations.
If your thyroid gland is not producing enough thyroxine, your doctor may prescribe levothyroxine. Without enough thyroxine in your body, you might notice symptoms such as weight gain, fatigue, dry skin and hair loss. Levothyroxine replaces the lost hormone, which usually results in a reversal of symptoms. Unlike most medications, levothyroxine is better absorbed on an empty stomach. Calcium can affect absorption of levothyroxine. Other medications can also interact with the hormone, so advise your physician of any other drugs you are taking.
Calcium with Vitamin D Identification
Calcium is a mineral that is needed by the body for many different metabolic functions and bone health. Although calcium is an abundant mineral, many people don't get enough calcium from diet alone. For this reason, calcium is available in supplemental form. Vitamin D aids in calcium absorption and is often included in calcium supplements for that reason. The Food and Nutrition Board recommends that adults up to the age of 50 consume 1,000 milligrams of the mineral per day. Women older than 50 need more calcium to prevent osteoporosis.
Calcium with vitamin D can negatively interact with levothyroxine, according to the Drugs.com interaction checker. Any calcium-containing product can decrease the absorption of levothyroxine by as much as one-third when taken at the same time. Although the exact mechanism of the interaction is not well understood, the mixture of levothyroxine and calcium causes acidic pH levels that are poorly absorbed. This moderate interaction applies to any product containing calcium, not just calcium supplements with vitamin D.
Consult your physician if you are taking levothyroxine and calcium with vitamin D for exact recommendations. Because the interaction only occurs when calcium and levothyroxine are taken together, some health care practitioners recommend spacing your dosage. Wait at least four hours after you take your levothyroxine before you take a calcium supplement with vitamin D. Keep in mind that food or medications containing calcium, such as antacids, can also interact with your medication if taken concurrently.