Posted by sues-health on July 10, 2007 at 01:24:15 PM

If a little is good, more must be better, right?

Unfortunately too many people believe this when it comes to taking dietary supplements.  Some vitamins and minerals are actually harmful when taken at high dosages.

Take selenium for example.  Selenium functions as an antioxidant in the body, working with vitamin E and thyroid hormone.  The daily requirement for adults is 55ug per day, however toxicity can develop with intakes over 400ug per day.  Toxicity symptoms include loss and brittleness of nails and hair, irritability, fatigue, nervous system disorders and garlic breath odor.

You can also add increasing the likelyhood of developing Type 2 diabetes to the list if results of a recently published study prove to be accurate.  I'll spare you all the details of the study (however if you are interested, click here), but essentially what these researchers found was that long term doses of 200ug per day of selenium raised a person's chances of developing Type 2 diabetes. 

As in any research, care must be taken at interpreting results.  One study alone does not prove the relationship, however it is safe to say these results are interesting and will no doubt spur further research.

So what is the significance of all this for you?  You may be thinking this doesn't even apply to you  because you don't regularly take selenium supplements.  I suggest you take a look at any multivitamins you take routinely, some contain selenium so you actually may be getting more than you think you are.

Do you really need supplemental selenium?  In my opinion, no.

Selenium is found in soil, and thus vegetables and other plants grown in most areas of the country provide adequate sources of dietary selenium.  Even in areas that have low soil selenium levels, a large variety of foods from other areas of the country are available that provide selenium.  Seafood and organ meats are also good sources of selenium.  Deficiencies are relatively rare in the US.