Calcium Supplements and Thyroid Hormone Replacement

Calcium Supplements May Interfere With Thyroid Replacement Treatment

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Calcium supplements and thyroid hormone replacement can often conflict. Calcium does, in fact, interfere with your ability to absorb thyroid hormone medication.

Why Take Calcium Supplements?

Everyone needs calcium to help build and maintain strong bones throughout their lifetime. In addition, everything from the heart to the nerves needs calcium to function properly. If you don't get enough calcium, you could face health problems related to weak bones. Children may not reach their full potential adult height and adults may have low bone mass, which is a risk factor for osteoporosis.

Many Americans don't get enough calcium in their diets. Children and adolescent girls are at particular risk, but so are adults age 50 and older. Although diet is the best way to get calcium, calcium supplements may be an option if you aren't getting enough calcium through your diet.

But before deciding whether or not to take calcium supplements, you need to understand how much calcium you need, the pros and cons of calcium supplements, and which type of supplement to choose.


Hypothyroidism is an underactive thyroid which means your thyroid gland doesn't produce enough of certain important hormones. Hypothyroidism disrupts the regular balance of chemical reactions in your body. Most people don't have symptoms at first but over time, untreated hypothyroidism can cause many health problems including obesity, joint pain, infertility and heart disease.

Treating Hypothyroidism

Treatment for hypothyroidism almost always includes daily use of the synthetic thyroid hormone levothyroxine (Levothroid, Synthroid, and others). This oral medication returns hormone levels back to normal and can actually reverse the signs and symptoms of hypothyroidism.

The medication also gradually lowers cholesterol levels which may have risen as a result of the disease and may reverse any weight gain. Most people have to take levothyroxine for their lifetime but the dosage often changes. This is why your doctor usually checks your TSH level every year.

Calcium and Thyroid Treatment  

If you are taking any calcium supplements, including antacid supplements such as Tums that contain calcium, take them at least three to four hours apart from your thyroid medication.

Be careful about calcium-fortified drinks, such as orange juice, and again, be sure to take them at least three to four hours apart from your thyroid medication. 

You should also be careful about overdoing other calcium-rich foods around the same time as you take your thyroid medication. Some popular foods high in calcium include:

  • Milk
  • Yogurt
  • Cheese
  • Sardines
  • Dark leafy green vegetables including spinach, kale, turnips, and collard greens. (Note: when raw, these are also thyroid-slowing goitrogens.) 
  • Some calcium-fortified  breakfast cereals (i.e., Raisin Bran, Corn Flakes and Total.) 
  • Soybeans
  • Calcium-fortified soymilk, almond milk, and rice milk. 

For more information on how to take your thyroid medications, including issues involving coffee, and fiber and their ability to affect your thyroid, see: How To Take Your Thyroid Medication.

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Article Sources
  • References:
  • Mayo Clinic. Calcium and calcium supplements: Achieving the right balance.
  • Mayo Clinic. Hypothyroidism.