Are you taking Synthroid for treatment of an underactive thyroid gland? Here’s why you shouldn’t be taking it with calcium.
Because of the high rate of osteoporosis, it’s often recommended that women take calcium supplements. While calcium is an important mineral for maintaining bone health,
it may not be wise to calcium at the same time as the prescription medication Synthroid. Studies have shown that taking Synthroid with calcium supplements can decrease the absorption of Synthroid, which could cause problems for those being treated for an underactive thyroid gland.
What is Synthroid?
Synthroid is a medication commonly used to treat hypothyroidism or an underactive thyroid gland. It’s essentially a synthetic form of the natural thyroid hormone, a hormone important for regulating metabolism as well as the rate of heat and energy production by the body. When levels of natural thyroid hormone are too low, as with hypothyroidism, a person can feel sluggish, cold, and mentally slow. He or she may also gain weight and experience dry skin and muscle weakness. If insufficient amounts of Synthroid are used to treat this condition or if the Synthroid isn’t absorbed adequately, symptoms of hypothyroidism can develop.
Taking Synthroid with Calcium: A Study
A study published in the Journal of the American Medical Association showed that taking Synthroid with a calcium carbonate supplement reduced levels of circulating thryroid hormone levels. (free T4). Synthroid is absorbed by the small intestine and it’s thought that calcium interferes with this absorption, although there may also be another mechanism at play since some of the experimental subjects didn’t experience a decrease in thyroid hormone levels despite taking a calcium supplement. It seems that the acidity of the stomach plays a role in determining whether Synthroid absorption is affected by calcium. One hypothesis is that in the presence of strong acid, calcium is able to bind with Synthroid and form a complex that the small intestine can’t absorb.
How to Solve the Problem
Because taking Synthroid with calcium may decrease its absorption, it’s recommended that Synthroid not be taken within four hours of taking a calcium supplement. Synthroid also has the potential to interact with a variety of other drugs and even foods such as soybean flour, walnuts, iron-rich foods, and high fiber foods. For this reason, a doctor or pharmacist should always be consulted before taking Synthroid.
The Bottom Line?
Taking Synthroid with calcium can decrease its absorption which could interfere with the treatment of underactive thyroid conditions. To avoid this, Synthroid and calcium should be taken four hours apart. Caution should also be used when taking Synthroid with iron, other medications, and even with certain food products, especially high fiber ones. This is a medication that should be taken under close medical guidance.