Too Much Selenium?

I was reading an article today and it was talking about Selenium, and how much is too much. Here’s a quote:

"Too much selenium can be harmful. The difference between an optimal and toxic dose is small. The safe upper limit for adults is 400 micrograms a day. Doses of 1,000 micrograms or more a day can cause nausea, vomiting, hair loss, and other problems. "

I checked fitday and for the last year I’ve averaged about 600 micrograms per day. Should I be worried? I’m thinking maybe I should get tested to see if it’s doing damage. I know a lot of my daily intake averages are high due to all the lean meat I eat (B vitamins are over 600%). But compared to the RDA, my daily selenium intake is at 1019% of the RDA recommended daily dose. Is there any way to cut back on this??

Too much of anything is a bad thing. Lots of vitamins and minerals, when taken in excess, can do the same things. Unless you’ve had any of the symptoms you listed (nausea, vomiting, hair loss, “other”) I wouldn’t worry about it.

I wikipediad it, and it seems that there are more problems associated with having a LOW level of selenium than a high one.

it killed the alien in the movie ‘evolution’

Almost killed a dude on House. It must be true.

You just said that you were averaging 600mcg a day and that toxicity is 1000mcg a day. It doesn’t matter if it is over 1000% of the RDA, it is still below toxicity.

Unless you have noted symptoms in the past due to this intake, don’t worry about it (Unless brazil nuts are unaccounted for in your diet, in which case then your selenium may be a tad higher than you think)

And if it’s any reassurance, selenium is used up in antioxidant defense, so the more oxidation that occurs in your body (Via metabolic activity, which I assume is plentiful with you), the more selenium will be used, and the further from overdose you will end up. :slight_smile:

I know selenium is used to help rebuild glutathione (part of the body’s antiox defense system) and it would make sense that an athlete would use up more of it than the average person in antioxidant defense, because of the fact that the body’s antioxidant system is up-regulated when exercised. You got any recommendations about how much is potentially used up? 1.5X 2X, 3X? Who knows.

600mcg is quite a bit. Although you won’t know how it affects you without a blood test. Anyone had a blood test who also happened to track their intake? Also, now that I’m thinking about it, you’d have to keep in mind that ALA (alpha lipoic acid) and NAC N-acetyl Cysteine also have a role in the production of glutathione so most likely you’d have to know those values as well.

I also know that having a low level of glutathione will increase absorption of selenium, so maybe the reverse is true as well, in which case taking a non-toxic level is most likely just fine even if it’s 2-3X the RDA; although A, C, and E also affect absorption, so watch those values as well. If you take mega doses of any of those nutrients, then pay even more attention to a selenium intake that’s over 2X above RDA. Keep in mind, the RDA is around 55 mcg but 200 mcg is probably completely safe for athletes, but 400 is the upper intake level set by the Institute of Medicine of the National Academy of Sciences.

One study I found showed that an athelete’s antioxidant defense (via glutathione) was not dependent on blood selenium levels. Also, while selenium requirements are increased in athletes, the amount required is not directly tied to energy expenditure.

I’m not sure if that study took into consideration other factors like ALA or NAC levels. Also, you have to consider about 100 other factors that I don’t even know much about. For example, hormone levels can have a direct impact on things like glutathione, SOD, and catalase levels. For example, birth control pills increase glutahione and CAT enzymes. I think this would mean that selenium needs would be at least slightly increased in women on the pill, but I’m not sure if I’m thinking about this the right way.

I’d love if someone like Bill Roberts was able to chime in on the subject.