Too Much Selenium

About specific vitamines, minerals or fiber, for example
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avalon
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Too Much Selenium

Post by avalon »

Hey everyone :shock: ehh...

Who needs pleasantries... :D

Is anyone concerned about getting too much Selenium?
• 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.
Using CRON-o-Meter
http://spaz.ca/cronometer/

with 4 yolks and 4 Brazil nuts you're already at 766% That's sounds high. Is that high? Seems high.

On the other hand:

http://www.cspinet.org/nah/selen.html
Willett is also troubled by how quickly cancer rates dropped in the selenium-takers. "It's not impossible, but it's pretty unusual to see cancer rates go down right away."
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RRM
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Post by RRM »

Selenium is a pre-antioxidant, increasing the level of specific anti-oxidants made by the body. Relative high levels seem to be beneficial regarding cancer.
Luckily, the body can very effectively adjust the absorption rate to the intake levels; if you consume very much of it, the uptake rate is close to 10%, whereas uptake rates will be more close to 80 or 90% when very little selenium is consumed. This is for both protection and nutrient requirements. When you consume selenium in its natural package (natural foods), the body effectively controls uptake. With supplements thats a different ballgame.
Quix
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Post by Quix »

I know this is a fairly old post but I'm fairly new. And I hate to second guess something RRM says because lets face it I'm basically molding my dietary life around your advice. I just wanna convince my father who is a doctor and worries about that being to much selenium in a diet.

Any chance you have a reference to where you heard that your selenium absorption rate decreasing with the increase in the amount ingested naturally through food? I would love to put his worry to rest.

Thanks a lot for any help :)
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RRM
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Post by RRM »

Quix wrote:Any chance you have a reference to where you heard that your selenium absorption rate decreasing with the increase in the amount ingested naturally through food?
It is known to be true for all (semi-) metals (and also minerals such as calcium). When your intakje increases, the absorption rate decreases and the excretion rate increases (specifically in hair, urine and nails). All this considering a not too radical increase.
Of course it is very well possible to get a selenium intoxification if you over-do it. (if the absorption rate adjustment cannot keep up with the increase in intake)
Just listen to your body; if you dont feel like eating those nuts, dont do it.
And if your dad is worried, you can listen to him and simply moderate your nuts intake. Moderation is always good.
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Oscar
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Post by Oscar »

Be careful with eating too much coconut then ;)
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RRM
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Post by RRM »

Moved from another thread:
the foruth wrote:How much is really too much? The FDA suggests 70 mcg wich is way exceded if you eat a fair ammount of any nut especially Brazil nuts. But is there any harm to eating 1 cup of Brazil nuts a day?

Has anyone been affected by selenium toxicity on this diet? Thanks.
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RRM
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Post by RRM »

Moved from another thread
Iris wrote: What will be too much differs from person to person and time to time, I think :wink: But your body will definitively tell when it has had enough of it. You just won't feel like eating it any more. So if you listen to your body carefully, you'll be fine, I believe :)
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RRM
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Post by RRM »

Exactly.
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Mr. PC
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Post by Mr. PC »

So would this mean it is more dangerous to have too quick of a transient between low and high intakes of nutrients, than to have a constant low intake or a constant high intake?
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RRM
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Post by RRM »

yes, if the intake is moderately low or high.
Because if its not moderate,
you may build up excess or a deficiency over time.
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Mr. PC
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Post by Mr. PC »

Maybe than, rather than having a RDI, there should be a scale with minimum/maximum intakes to avoid toxicity / deficiency in the long term?
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RRM
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Post by RRM »

That has been done many years;
the maximum being only twice the RDA.
The difficulty with this is that the uptake percentage is not a given,
as it depends on how much is contained by your normal diet,
so that you cannot possibly tell what is the minimum or maximum,
as they depend...
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Post by Jodiat »

I agree with RRM the body adjusts its uptake depending on supply. In a nut shell if you over do it youll excrete more.

Selenium (naturally) is the last thing I would worry about in this big bad world. However the brazil nut does have 2 500 times the selenium of any other nut. Infact is brazil nut even a nut that is the question.
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