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Non-Vital Biological Functions of Elements

  1. May 18, 2016 #1

    Drakkith

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    I was reading the wikipedia article on Lithium and noticed that it says:

    Trace amounts of lithium are present in all organisms. The element serves no apparent vital biological function, since animals and plants survive in good health without it, though non-vital functions have not been ruled out.

    I'm just curious as to what sort of non-vital functions they might be referring to. Do other elements or chemicals have non-vital biological functions?

    Thanks.
     
  2. jcsd
  3. May 18, 2016 #2

    1oldman2

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    I'm sure there is more to it than the Wiki article mentions, take a look at this article. (not sure if Psych today is an approved source but it may be relevant)
    .

    https://www.psychologytoday.com/blo...atry/201201/could-you-have-lithium-deficiency
     
  4. May 18, 2016 #3

    OmCheeto

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    Here's an interesting article published by UC Davis:
    I interpret that as "They are still figuring it out".
    From the periodic table they display, lithium is labeled: Nonessential for humans

    I also found lots of fun articles on "lithium":

    A Negative Association Between Lithium in Drinking Water and the Incidences of Homicides, in Greece
    :oldsurprised:
    hmmm...... Lithium may not be essential for you, but the people around you might survive longer if you're not deficient. :oldbiggrin:
     
  5. May 18, 2016 #4

    Ygggdrasil

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    There are certainly many substances that are not vital to the human body but still have biological effects on the body. For example, drugs, both legal and illegal, have a variety of effects on the body. Lithium in particular has some uses in psychiatric medicine.
     
  6. May 19, 2016 #5

    jim mcnamara

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    Slightly different point -
    A stable Strontium isotope, outside of medical applications, may be found in human bone, especially in areas where the element occurs in deposits. It is apparently harmless in small quantities. The way I used to explain this: in food and water there can be tiny amounts of oddball impurities, like strontium. The strontium atom is chemically very similar to calcium, so your biological metabolic pathways treat it like calcium. It gets parked in bone, for instance.

    Also note that trace amounts of some elements get relegated to the "outbound biological highway": growing hair follicles. Which gets the element out the way biologically. Fat is also a dumping ground for toxins. Argyria is an example.

    Some elements are so ubiquitous and occur in tiny, tiny amounts that AFAIK some are still labelled 'ultratrace' elements in nutrition:
    http://www.annualreviews.org/doi/abs/10.1146/annurev.nu.04.070184.000321

    Silicon example: it is REALLY difficult to get every single silicon atom out of water and food for animals, so silicon dietary requirements have not been determined for humans or livestock.

    And then there is silver: https://en.wikipedia.org/wiki/Argyria Blue aliens in the movies have nothing on people who take lots of colloidal silver, for example.
     
  7. May 19, 2016 #6

    Drakkith

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    Oh god! That's crazy!!
     
  8. May 19, 2016 #7

    Andy Resnick

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    Several elements have no known biological function:

    http://scienceblogs.com/startswithabang/files/2013/06/daves-elements.jpg

    As for Lithium, it does appear to have a biological function (I don't know about 'vital', tho):

    http://link.springer.com/book/10.1007/978-1-4612-3324-4

    Most of the elements I looked up seem to be better studied in plant physiology, of which I know nothing.

    This article seems worthwhile:

    http://www.encyclopedia.com/topic/Trace_Elements.aspx
     
  9. May 20, 2016 #8

    jim mcnamara

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    @Andy Resnick - Agriculture colleges have studied micronutrients in livestock extensively. Example: selenium

    The story I got was pig farmers in some regions of the US state Iowa were having issues with growing pigs. The Ag college folks saw the Schwarz paper, and they worked through a lot of issues. That spread throughout the animal husbandry researchers.

    Really interesting history - https://www.asas.org/docs/publications/oldfieldhist.pdf?sfvrsn=0
     
  10. May 20, 2016 #9

    Andy Resnick

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    Selenium is interesting- it is an essential nutrient in our (mammalian) cell culture media. The amino acid it forms, selenocysteine, was discovered in the 1970's:

    https://en.wikipedia.org/wiki/Selenocysteine
     
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