Do I Have a Selenium Deficiency? --- Different Selenium Tests Give Different Answers

[Bird_42]

Hi. I am a 39-year-old male, and I have hypothyroidism.


Back in July 2011, I suspected that I had a problem with FT4-to-FT3 conversion.  Because deficiencies in Selenium and Vitamin E could interfere with FT4-to-FT3 conversion, I had blood tests for these substances. The results were as follows:

Selenium (serum or plasma) = 150    (normal range = 79 - 326 ug/L) (detection limit = 10 ug/L)

Vitamin E (Alpha Tocopherol) (serum) = 7.0    (normal range = 3.0 - 15.8 mg/L)

Because these results were within the normal ranges, I thought that I did not have any deficiencies, and I did not take any supplements.



In January 2013, someone on this forum said that her Selenium levels had been within the normal range but that they had been in the *low* normal range. She started taking Selenium supplements and felt much better. In other words, a Selenium value that was in the "low" normal range still indicated deficiency.

So, I went back to my results from July 2011. The Selenium value was in the lower one-third of the normal range for Selenium, and the Vitamin E value was in the lower one-third of the normal range for Vitamin E. So, it appeared that I might have deficiencies in Selenium and Vitamin E after all.



In early March 2013, I decided to get re-tested for Selenium and Vitamin E. The results were as follows:

Selenium (serum or plasma) = 161    (normal range = 79 - 326 ug/L) (detection limit = 10 ug/L)  

Vitamin E (Alpha Tocopherol) (serum) = 7.8    (normal range = 4.6 - 17.8 mg/L)    

My Selenium level was in the lower one-third of the Selenium normal range, and my Vitamin E level was in the lower one-fourth of the Vitamin E normal range.





I still did not take any Selenium or Vitamin E supplements, and in mid-May 2013, I was tested for Selenium and Vitamin E yet again.


The Vitamin E result was as follows:

vitamin E (Alpha Tocopherol) (serum) = 7.7    (normal range = 4.6 - 17.8 mg/L)    

This result, like the previous result, was in the lower one-fourth of the Vitamin E normal range.


However, the Selenium result was very weird. The endo sent me an email telling me that the result was
296 ug/L (normal range = 100 - 340 ug/L). How had the Selenium skyrocketed from 161 to 296 in only 2.5 months? Well, it turned out that the endo had ordered the incorrect test. Instead of ordering the Selenium (serum or plasma) test, she had ordered the Selenium (blood) test. 296 ug/L was the Selenium (blood) value. (I've had this endo for less than a year, and this is the SECOND time she has ordered the wrong test. UGH!!!)


But the Selenium (blood) value does raise some interesting questions. The Selenium (blood) value is in the upper one-fourth of the Selenium (blood) normal range, while the Selenium (serum or plasma) value from 2.5 months earlier is in the lower one-third of the Selenium (serum or plasma) normal range. So, which test is the more accurate test of my Selenium level? If my Selenium (serum or plasma) value is in the low normal range and my Selenium (blood) value is in the high normal range, then do I have a Selenium deficiency?



Thanks for any info.

[mylo5]

Working with livestock,  I can tell you that there's better nutritional information available in the animal health world than the human's.  In line with that I have copied the following bit about testing for selenium in cattle and am providing a link if you are interested in reading about other minerals also.

Diagnosis of a [selenium] deficiency can be made by analysis of liver, whole blood, or serum for selenium content or by analysis of whole blood for activity of glutathione peroxidase, a selenium-dependent enzyme. The most specific analysis is that of whole blood glutathione peroxidase, as it verifies true functional selenium status. Liver is the optimal tissue to analyze for selenium content, as it is a primary storage tissue. With serum and whole blood, the former better reflects recent intake, while the latter better reflects long term status. Since seleno-proteins are incorporated into the red blood cells when they are made and the cells have a long half-life, selenium content is a reflection of intake over the previous months. In order to adequately diagnose selenium deficiency, the dietary form of the selenium intake by the animals is important. Natural selenium, predominantly in the form of selenomethionine, is metabolized and incorporated into selenium dependent proteins, but can also be incorporated into non-specific proteins in place of methionine. This means that selenium from these sources can be deposited in muscle and other tissues. Inorganic selenium is metabolized and only incorporated into selenium dependent proteins but this does include the very important availability to the synthesis of glutathione peroxidase. Thus, “normal” concentrations in serum and whole blood differ depending on whether the dietary selenium is a natural organic form or an inorganic supplement.
http://www.cattletoday.com/archive/2006/April/CT460.shtml

[goolarra]

I know little about selenium testing.  However, looking at it logically, the two ranges (79-326 for serum or plasma and 100-340 for blood) are almost identical.  Were they done at different labs or even at the same lab that had changed their range in the interim?

I have a known deiodinase problem.  As you've probably read, deiodinases are selenium based enzymes that catalyze the conversion of T4 to T3.  So, a few years ago, as a self experiment, I started taking selenium (I didn't have levels tested first...shame on me!).  Just after adding the selenium, my FT3 level jumped considerably.  I had done nothing else differently, so I assumed (and you know what happens when you assume) it was the selenium.  I continued it for several years until my FT3 went into a tailspin on the same dose of selenium.  I've since discontinued it, and nothing seems to have changed.

Can you explain the increase in selenium by your diet?  Did you suddenly develop a penchant for Brazil nuts?  Shellfish or other fish?  Sunflower seeds?  Liver?  Did you move to a different part of the country?

I guess you might ask for a repeat of the serum or plasma test so you can compare it to your history.