From: ((Steven B. Harris)) Subject: Re: selenium Date: 18 May 1995 Newsgroups: sci.life-extension In <email@example.com> firstname.lastname@example.org (Steven Wm. Fowkes) writes: > Selenomethionine must be >catabolized (broken down) to release free selenide in order to >incorporate selenium into glutathione peroxidase. Selenomethionine is >treated like methionine by the body. Selenomethionine is incorporated >into proteins just like methionine, and it tends to accumulate in >proteins. This causes cummulative toxicity. Wups, no, this is the old view. It is now known that there is a special codon at the site of selenomethionine in both DNA and RNA for proteins like glutathione peroxidase and the thyroid inner ring deiodinase, which incorporate this amino acid at an active site. Thus, selenomethionine is NOT a post translation modification to proteins, but rather is a 21st amino acid specified by the RNA code, with its own special transfer RNA. There is some evidence that selenomethionine gets incorporated into other proteins at (I believe) serine sites, so this system may not be perfect (this codon also codes for serine). Steve Harris, M.D.
From: email@example.com (Steven B. Harris ) Subject: Re: Poisonous Plants (Inorganic Poisons) Date: 26 Jul 1995 Newsgroups: sci.bio,rec.food.cooking,sci.med.nutrition In <dylanyDC78B8.1vA@netcom.com> firstname.lastname@example.org (Dylan Yolles) writes: >email@example.com wrote: >> Sure. Certain species of Oxytropis and Astragalus ("locoweeds") >> concentrate selenium-- actually they incorporate selenium into amino >> acids in the places where ordinary plants and animals use sulfur-- the >> so-called "sulfur-sparing metabolism". Se and seleno-amino acids are >> pretty good mammalian neurotoxins. > >I have a bottle of vitamins here which contain 10 mcg of Selenium in the >form of Selenium Selenite. (In fact - they come from Trader Joe's.) >Should these be avoided? Inorganic selenium is not too poisonous, and you can take 250 mcg forever without danger. Apparently you can even take 1000 mcg a day with risking nothing more than bad breath and a garlicy sweat. 5000 mcg (5 mg) a day and up is considered poisonous. However, I've read stories of selenium workers at rectifier plants who had so much selenium in them that their fingernails turned red from crystals of the reduced element under the nailbed. So some people can tolerate a LOT of inorganic selenium. The organic amino-acid stuff is another matter, possibly. Steve Harris, M.D.
From: firstname.lastname@example.org (Jay Mann) Newsgroups: sci.med.nutrition Subject: Re: Modern soils depleted of vitamins? Date: 19 Nov 1997 18:26:37 GMT Ian Woollard (email@example.com) wrote: : Jay Mann wrote: : > Since plants in general require similar minerals to those needed : > by animals, a depleted soil would be a poor-yielding soil. : : That's somewhat true, but there are some big exceptions. One : notable exception is selenium. Plants don't need selenium to : grow at all- animals most definitely do. Most plants don't, but some Astragalus species require selenium, and have accordingly been used as bio-markers for high-selenium soils. I think these species are toxic to grazing animals because of their selenium content. : There is a very high negative correlation between the level : of selenium in the soil of different countries and the level : of breast cancer in those countries. (Not that that is the : whole story, but selenium does appear to protect against : this disease.) Here in NZ where we have naturally low-selenium soils, a muscle-wasting disease of sheep is prevented by "drenching" the animals with selenium supplements. (A "drench" is not necessarily a bath, and in this case is a squirt of liquid into the animal's mouth.) In one region of China, where children in their teens were dying of heart attacks, selenium supplementation almost completely stopped these problems. Again, this shows a connection between muscles and selenium. You won't be surprised that selenium pills are fairly popular here among city folk who don't have access to sheep drench. Otherwise it's too risky: if you eat bread made from NZ wheat, and don't eat seafoods, you might not be getting enough selenium. But if the bread flour came from Australian wheat, you're ok. Why take a chance? : Areas that are low in selenium include the UK, Canada (and as : far as I can recall the US.) One region of China, Finland, and the South Island of New Zealand are, I think, the prize winners for low-selenium soils. In Finland, farmers are required to treat their soils with selenium. Jay
From: firstname.lastname@example.org (Jay Mann) Newsgroups: sci.med.nutrition Subject: Re: what is the use of sernium in human body? Date: 4 Dec 1997 19:36:07 GMT Chairo (email@example.com) wrote: : : sernium is a minor mineral for human body....but what's it usage? I think you are referring to selenium. My bottle of selenium supplement contains 100 micrograms (that's 0.1 milligram) of selenium. Unless you live in the selenium-deficient province of China (don't recall its name) you probably don't require any supplementation. And since HongKong is famous for its seafood restaurants, where seafood is rich in selenium, that's yet another reason not to be concerned. I take selenium because New Zealand soils are deficient in selenium, which means locally grown wheat is also deficient. Jay D Mann <firstname.lastname@example.org> Christchurch, New Zealand
From: email@example.com(Steven B. Harris) Newsgroups: sci.med.nutrition Subject: Re: what is the use of sernium in human body? Date: 5 Dec 1997 00:08:28 GMT In <firstname.lastname@example.org> email@example.com (Jay Mann) writes: > >Chairo (firstname.lastname@example.org) wrote: >: >: sernium is a minor mineral for human body....but what's it usage? > >I think you are referring to selenium. My bottle of selenium supplement >contains 100 micrograms (that's 0.1 milligram) of selenium. Unless you live >in the selenium-deficient province of China (don't recall its name) you >probably don't require any supplementation. On the contrary, a recent study in which Americans were randomized to either 200 mcg a day or placebo showed a 50% reduction in many nasty cancers, including prostate cancer. That's quite a useful thing, to be able to decrease your major cancer risk by 50% just by taking a pill. Steve Harris, M.D. [[ Note: Since this was written, the selenium / cancer link has been studied in a huge trial, and seems not to be significant; see the SELECT trial homepage at: http://www.crab.org/select/ -- Norman ]]
From: email@example.com(Steven B. Harris) Newsgroups: sci.med.nutrition Subject: Re: what is the use of sernium in human body? Date: 6 Dec 1997 12:31:43 GMT In <3488EC60.29CC@erols.com> firstname.lastname@example.org writes: > > But China is where most of the selenium toxicity studies have been >done, due to their HIGH selenium content. I suppose some areas are >deficient also. Yep. The region of Keshan, for instance. People there get a characteristic cardiomyopathy, which is probably due to an inadequate immune response to a particular virus which causes cardiomyopathy if not dealt with effectively. It's not strictly a selenium effect on the heart at all, but rather on the immune system. Which is not surprising, since in animals selenium deficiency to the point of causing pathology is extraordinarily hard to produce (you need to be vitamin E deficiency also), and usually involves the liver, not the heart. And, of course, spontaneous cancer incidence goes up. Steve Harris, M.D.
From: email@example.com(Steven B. Harris) Newsgroups: sci.med.nutrition Subject: Re: selenium(200mcg) info? Date: 14 Jun 1998 06:35:58 GMT In <firstname.lastname@example.org> email@example.com (Alf Christophersen) writes: >"EricP" <EricPsor@usa.net> wrote: > >>I weight about 140 lbs plus/minus 5 lbs, so it would translate to >>about 305-325 mcg/day max. for my case. Are there any foods >>(especially vegetables and fish) that contains more than 100 mcg of >>selenium? In other word, what food sources that are rich in selenium? > > >Depends on where you live and from where your food comes. > >There are areas in US that has almost as low Se content as in Europe, >while others are very rich in it, and some few places so high that the >content may be chronically toxic. Other places in world it may even get >up in acute toxic doses. Yes, though in these days of refrigeration and world wide produce markets, it all tends to even out. Selenium in soils is basically in the soluable selenate form, which is leachable by water. It comes up in volcanic cinder cones,and when it rains, it leaches out into water systems (occassionally reaching toxic levels, as in Kesterton). Land which was once at the bottom of some old lake or ocean tends to be high selenium, therefore, as is volcanic soil which is fairly new. The rest (all other soils) are long leached out. Most large countries therefore have areas which are very high in Se and others which are very low, simply because of the leaching effect. Example: once upon a time they had to ship feed from South Dakota (high in Se) to Ohio (low in Se) to take care of the selenium imbalance in those states. But these days, as I said, the shipping of produce is so mobile that it's not much of a problem any more. Steve Harris, M.D.
From: firstname.lastname@example.org(Steven B. Harris) Newsgroups: misc.health.alternative,sci.med.nutrition Subject: Re: selenium(200mcg) info? Date: 12 Jul 1998 04:45:27 GMT In <email@example.com> suequill <firstname.lastname@example.org> writes: >Also, can't find the connection for it now, but Dartmouth Hitchcock >Medical Center 16 July 97 stated, that they have demonstrated a >crucial role for selenium in the control of thyroid hormone effects >in the brain and fat tissue. The deiodinase which converts T4 to T3 is known to be a selenium enzyme-- the second discovered after glutathione peroxidase, I believe. This might be a little more important for people with hypothyroidism who are taking T4 replacement only. So far, I haven't been able to find any reports of clinical thyroid effects attributable to Se levels, but who knows what future research will yield. Often you don't find what you don't look for, and the Se/thyroid connection hasn't been known for less than a decade. As for which form of Se is best, note that most of the animal anticancer studies have been with the inorganic salt. The latest positive human study used selenized yeast (selenomethione). I suspect it doesn't matter which you take. But we don't know for sure about that, either. Suspenders and belt people will take both forms, perhaps 200 mcg of each. That ought to pretty much take care of you, and still stay way below tox range. Tell you loved ones and friends to be on the lookout for garlic sweat and garlic breath on you-- the very first sign of slow and chronic Se overload. If you don't specifically tell them, they'll just think you eat pizza all the time. Steve Harris, M.D.
From: email@example.com(Steven B. Harris) Newsgroups: sci.med.nutrition Subject: Re: Selenium toxic? Date: 14 Aug 1998 19:07:22 GMT In <e440AH5x9GA.185@upnetnews05> "Jim" <firstname.lastname@example.org> writes: >One critical aspect aside form the potency is the source of selenium. The >inorganic salts, i.e. Sodium Selenate (or Sodium Selenite) or any other >salt freely disassociates in the GI tract leaving free selenium, which >has serious toxicity, although I do not believe there have been studies >specifically on these forms to determine toxic levels. On the contrary, I resist the notion that selenium as the inorganic salt is any more toxic than selenium as incorporated into amino acids. They are interconvertable in the body, and the selenoamino acids in muscle represent a long term storage pool. Much as in the case with vitamin A, you don't start seeing chronic selenium toxicity (the garlic breath, etc) until that storage pool is overwhelmed (of course, VERY high doses of selenium can cause toxic symptoms immediately). Seems to me that yeast would be just as effective at doing this (overloading your stores) as any other form. Indeed, I've seen balance studies which indicate that the Se in selenomethione is better retained by the body than the Se in SeO3= or SeO4=, so this form may be even MORE liable to produce toxicity at a given chronic dose (ie, there may be some equivalence ratio between organic and inorganic Se; I just don't know what it is). One other thing to remember-- most of the animal experiments showing the anticancer properties of selenium were done with the selenite salt. It's just as good a form of selenium as any other. If you're paying good money for a yeast selenomethionine that's a lot more expensive per mcg than selenite, you're probably wasting $. On the other hand, looking at the market, there are only a few selenite and selenate preparations around (Twinlab, VRP), and they're just as expensive as the selenomethione, which is produced in huge quantities by the selenized yeast people, and is rapidly becoming the industry standard. The howler being that your body probably has to break down selenomethione all the way to inorganic Se to make selenocysteine <g>. Steve Harris, M.D.
From: "Steve Harris" <sbharris@ix.RETICULATEDOBJECTcom.com> Newsgroups: sci.med.nutrition Subject: Re: Two selenium questions. Date: Mon, 6 May 2002 22:48:05 -0600 Message-ID: <email@example.com> "tintinet" <firstname.lastname@example.org> wrote in message news:email@example.com... > Elmer Ogryzlo <firstname.lastname@example.org> wrote in message > news:<ogryzlo-30C45D.email@example.com>... > > In article <3CD4FEA8.firstname.lastname@example.org>, > > Ann R Quay <email@example.com> wrote: > > > > > What is it that makes a selenium supplement smell like stinky feet? > > > If a person took this supplement would they come to smell like that as > > > well? > > > > The answer is yes, if you took much more than the recommended > > supplement. I had a student working with selenium (hydrogen selenide > > actually) which not only is very smelly (like it's cousin hydrogen > > sulphide) but the student found that it was absorbed by his clothing and > > body (lungs?). Not only did his family complain about the odors > > emanating from his body and clothing, but he often remarked that he > > noted on many occasions that there were more than a few empty seats > > around him on the bus although the rest of the bus was crowded. > > > > Elmer > > That might almost be humorous if selenium weren't toxic in slightly > higher than normal doses. I doubt supplementation of 200 mcg/day > causes perceptibly increased b.o. COMMENT The toxicity is overrated-- in industry people have been loaded with so much selenium that the allotrophic deposits under their fingernails turned them red. It's only when the nails start to fall OUT that you need to worry.... And yes, long before that, selenium will give you a rather garlicy body odor and breath. Being an unusually good retainer of the stuff, I can begin to smell selenium in my sweat at 400 ug a day, and I can taste it in the mornings at only 200 ug a day. So 100 ug a day in a supplimentation is my practical limit. SBH