http://articles.mercola.com/sites/articles/archive/2000/06/10/calcium-thyroid.aspxThis study showed that the use calcium carbonate (e.g., Tums, Rolaids, Os-Cal, etc.), may interfere with the use of synthetic thyroid hormone, levothyroxine (Synthroid). It is proposed that the calcium carbonate binds to thyroxine (T4), especially inenCommunityServer 2008.5 SP1 (Build: 31106.3070)http://articles.mercola.com/sites/articles/archive/2000/06/10/calcium-thyroid.aspx#40390Thu, 18 Sep 2008 20:34:42 GMT24451277-a5aa-4add-96dc-64081bfd86fa:40390Alancola<p>I currently take 100 micrograms of thyroxine each day with 50 mils of spring water early in the morning about 2 -3 hours before breakfast. This water contains 7 mg of calcium per litre (which is quite low for spring water). I then allow at least 4 hours to pass before partaking of my daily yoghurt containing about 150 - 250 micrograms of calcium. Will the 0.35 mg present in the water I take with the thyroxin or my daily intake of about 250 micrograms of calcium effect my T4 and TSH levels</p> <img src="http://articles.mercola.com/aggbug.aspx?PostID=40390" width="1" height="1">