Apparently well water can have a high calcium and magnesium content depending on where you live and the type rock, etc. the water filters through. Our well water does contain high magnesium and calcium, as well as a small amount of iron.
In the morning when I take my thyroid replacemnt hormone I drink bottled water and make the A.M. coffee with bottled water because the calcium and iron content of our well water is high enough to interfere with the pill’s absorption. I usually wait 2-3 hours after taking my pill to drink the well water.
If you are currently getting your water from a well you may want to take your meds with bottled water. If you aren’t sure what the mineral content of your water is then you may want to have it tested. Usually the county Health Dept. can test for potability and mineral content for free or for a small fee. Sometimes places that sell bottled water or softening systems will test water for free too. We have ours tested by the Health Dept. every 2 years just to make sure there is no problem with agricultural run-off. To me, ‘city water’ takes terrible.
