Natural health: Should people take selenium supplement

Q: I have read that our soil is deficient in selenium and everyone should take a selenium supplement to address this. What do you suggest?

A: Unless you have been tested and know that your selenium levels are of concern, it is best to proceed with caution. An effective way to check your selenium levels is by checking the conversion of the inactive thyroid hormone (T4) to the active thyroid hormone (T3). If you have about half the amount of T3 compared to your T4 then you are doing well (a ratio of 2:1 T4:T3). Illnesses in which low selenium levels have been implicated include diabetes, heart disease, cancer, high cholesterol, arthritis, hypothyroidism, psoriasis, and depression.

Selenium is only required in such a small quantity (it is thought that we only need 50-70 micrograms daily) that the margin for error is also very small. Plasma concentration of selenium measured at 1mg/L indicates that it is working effectively against free radicals in our body. A reading of 2mg/L, just a milligram higher (equivalent to 1,000 micrograms), indicates that the selenium in our body is actually triggering oxidation.