Iron and calcium supplements can interfere with how your body absorbs thyroid medications. So space these at least 1 hour apart. Another supplement to watch out for is biotin. It's commonly taken for its hair, skin, and nail benefits.
As mentioned above, levothyroxine should not be taken within 4 hours of medications and supplements like antacids, bile acid sequestrants, ion exchange resins, iron supplements, or calcium.
Interactions between your drugs
No interactions were found between levothyroxine and Vitamin D3. However, this does not necessarily mean no interactions exist. Always consult your healthcare provider.
No interactions were found between levothyroxine and Vitamin C.
Like hormones, minerals like iron and calcium can bind to thyroid hormone and inhibit absorption. A good rule of thumb: “Take your thyroid hormone first thing in the morning, on an empty stomach, and take multivitamins and other supplements at lunch, at least 4 hours later,” suggests Levy.
Some medications, such as antacids, omeprazole (Prilosec), and phenobarbital, could lessen how well levothyroxine works. And this could mean you're not getting enough thyroid hormone. But other medications, such as amiodarone (Pacerone) and beta blockers, could make its effects too strong.
A number of drugs have been shown to impair the absorption of levothyroxine; these drugs include calcium carbonate, aluminum- containing antacids, sucralfate, iron supplements, cholestyramine, sevelamer, and, possibly, ciprofloxacin, raloxifene, and orlistat.
Supplements: Calcium supplements can inhibit the absorption of levothyroxine, and for this reason, should be taken at least four hours after taking levothyroxine, or longer, if taking high doses of calcium (i.e., more than 500 mg). Similarly, iron supplements may interfere with absorption of levothyroxine.
According to the Mayo Clinic, supplements such as calcium, iron, multivitamins containing iron, and antacids containing magnesium or aluminum can potentially have interactions with thyroid medications.
Doctors suggest taking Vitamin B12 in doses higher than the recommended dosage of 200-1,100 pg/ml for those who are taking thyroid medication simultaneously.
No interactions were found between Fish Oil and levothyroxine.
4. Vitamins and supplements. “You should also avoid any drugs or supplements that contain iron, calcium, or magnesium for at least four hours after taking your thyroid medications,” says Dr. Jaiswal.
levothyroxine magnesium oxide
Taking levothyroxine and magnesium oxide too close together may interfere with the absorption of levothyroxine and reduce its effectiveness. To prevent or minimize potential interaction, these medications should preferably be taken at least four hours apart.
Using multivitamin with minerals together with levothyroxine may decrease the effects of levothyroxine. You should separate the administration of levothyroxine and multivitamin with minerals by at least 4 hours.
Products such as iron and calcium supplements and antacids can lower your body's ability to absorb levothyroxine, so SYNTHROID should be taken 4 hours before or after taking these products.
“The results demonstrate that the absorption of levothyroxine sodium oral solution was not affected by the consumption of coffee, potentially offering patients and providers more dosing flexibility,” Washington said.
Not enough iodine.
Too little iodine can lead to hypothyroidism. Too much iodine can make hypothyroidism worse in people who already have the condition. In some parts of the world, it's common for people not to get enough iodine in their diets.
Supplementing with B12 may lead to an improvement in hypothyroid symptoms.
Interactions between your drugs
No interactions were found between levothyroxine and Vitamin B12.
No interactions were found between levothyroxine and Vitamins. However, this does not necessarily mean no interactions exist. Always consult your healthcare provider.
In conclusion, bedtime intake of levothyroxine in our study significantly improved thyroid hormone levels. This may be explained by better gastrointestinal bioavailability at night or by less uptake interference by food or medications. As shown in this study, bedtime administration is more convenient for many patients.
The absorption of levothyroxine is approximately 80% after oral administration. Certain drugs have been shown to interfere with the absorption of levothyroxine. These include ferrous sulfate,3 sucralfate,4,5 bile acid sequestrants used to treat hypercholesterolemia,6 and aluminum hydroxide given as an antacid.
Food, dietary fibre and espresso coffee interfere with the absorption of levothyroxine. Malabsorptive disorders reported to affect the absorption of levothyroxine include coeliac disease, inflammatory bowel disease, lactose intolerance as well as Helicobacter pylori (H. pylori) infection and atrophic gastritis.