# Minimum Number of Elements We Could Get By With **URL:** \ **Category:** Factual Questions\ **Created:** [November 8, 2008, 4:50am UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771 "2008-11-08T04:50:40Z")\ **Posts on this page:** 19\ **Page:** 1
**Author:** ![Markxxx](https://avatars.discourse-cdn.com/v4/letter/m/5daacb/32.png) [@Markxxx](https://boards.straightdope.com/u/Markxxx)\ **Post date:** [November 8, 2008, 4:50am UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/1 "2008-11-08T04:50:40Z")
I’ve been reading some physics books with the orgin of life and I got to thinking, what is the minimum number of elements humans would need to have on earth to live. By this I mean, of course we would need elements like Oxygen, Calcium, Carbon, Nitrogen, Iron, Magnesium, Zinc, and so forth. But for instance, would we need uranium to live? Could humans get by without it? For the purpose of this question, I mean elements humans need to live. In other words, element that allow us to be born, eat properly, maintain health, reproduce and die. Just like animals. I don’t mean elements would allow us to build skyscrapers or rocket or guns or stuff like that. So what elements don’t we need. Or would it be easier to name the ones we do? Thanks ---
**Author:** ![Shalmanese](https://avatars.discourse-cdn.com/v4/letter/s/45deac/32.png) [@Shalmanese](https://boards.straightdope.com/u/Shalmanese)\ **Post date:** [November 8, 2008, 5:22am UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/2 "2008-11-08T05:22:36Z")
I believe radioactive decay from uranium provides heat and drives convection currents that keep the earth habitable to life. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [November 8, 2008, 12:02pm UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/3 "2008-11-08T12:02:28Z")
> [@Markxxx](#): > > By this I mean, of course we would need elements like Oxygen, Calcium, Carbon, Nitrogen, Iron, Magnesium, Zinc, and so forth. Besides the above, hydrogen. potassium, phosphorus, selenium, copper, sodium, chlorine, sulfur, chromium, nickel, iodine, cobalt, manganese, molybdenum, vanadium, boron, and silicon all have some function in the human body. The functions of boron and silicon are not known, but they seem to be needed. Other elements, such as strontium, lithium, and fluorine, have medicinal uses but are not known to be required for human health. Tungsten and cadmium are essential to some non-human forms of life and there are certain bacteria that get energy from reducing arsenic compounds. > [@](#): > > But for instance, would we need uranium to live? Could humans get by without it? Definitely not an essential element. But like many elements, it’s found disolved in water in low concentrations, so you have some in your body anyway. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [November 8, 2008, 12:19pm UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/4 "2008-11-08T12:19:01Z")
Apparently, tin is also an essential element. ---
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [November 8, 2008, 3:10pm UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/5 "2008-11-08T15:10:21Z")
Quite a number of elements are essential in trace quantities, such as selenium, for instance. Webelements has a page on the biology of each element: > **[The periodic table of the elements by WebElements](https://www.webelements.com/biology.html)** > > Explore the biology of the chemical elements through this periodic table > **[WebElements Periodic Table » Selenium » biological information](https://www.webelements.com/selenium/biology.html)** > > This WebElements periodic table page contains biological information for the element selenium You also don’t want to overlook things like chlorine which are present in some very important compounds - the hydrochloric acid in your stomach, for instance. Chlorine and sodium are also wrapped up in table salt. Ones you start considering the foodstuffs for a feasible diet, a lot more elements will come in. It’s going to be very difficult to answer this. Do you want to include elements that aren’t required for human metabolism, but are necessary to support the Earth’s ecological system, or some other organisms? If it’s only required by certain organisms, are those ones we can do without? Vanadium, for instance, is concentrated and used by sea squirts. When I looked up the webelements entry, I find no mention of it being essential for humans, but it is required in trace quantities in rats and chicks. It’s also likely that we don’t KNOW about all the trace dietary requirements of the human body, and something not considered “essential” actually is. ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [November 8, 2008, 5:33pm UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/6 "2008-11-08T17:33:50Z")
Also, there may be trace elements which are required, but which wouldn’t be needed with a little evolution. Elements which were always around, so we evolved to use them, but for which an alternative element could be used instead, perhaps a little less efficiently. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [November 8, 2008, 7:57pm UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/7 "2008-11-08T19:57:54Z")
The noble gases are chemically inert and other than argon are pretty rare anyway. Hard to see how we’d miss them. ---
**Author:** ![Markxxx](https://avatars.discourse-cdn.com/v4/letter/m/5daacb/32.png) [@Markxxx](https://boards.straightdope.com/u/Markxxx)\ **Post date:** [November 8, 2008, 9:10pm UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/8 "2008-11-08T21:10:00Z")
> [@ZenBeam](#): > > Also, there may be trace elements which are required, but which wouldn’t be needed with a little evolution. Elements which were always around, so we evolved to use them, but for which an alternative element could be used instead, perhaps a little less efficiently. Yes see this is the kind of thing I was looking for. I’ve been reading some physic books and they always say “If this had gone just slightly the other way, this wouldn’t have happened, and life couldn’t have formed.” So I got to wondering, just what kinds of elements we could use. Like we make cans out of aluminum but we could use tin. So I was thinking if we just want humans to basic, just like the animals, you know, birth, live, reproduce, die… What kinds of elements do we REALLY need. It looks like we do need most of them, so perhaps it’d be easier to think of the ones we could get along with. Again I’m just talking basics. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [November 8, 2008, 10:21pm UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/9 "2008-11-08T22:21:33Z")
> [@Markxxx](#): > > I’ve been reading some physic books and they always say "If this had gone just slightly the other way, this wouldn’t have happened, and life couldn’t have formed. A recent discussion of the Weak Force in nuclear physics lead me to research the subject and this Wiki page, arguing that human life doesn’t intrinsically need one of the fundamental forces of the universe: > **[Weakless universe](https://en.wikipedia.org/wiki/Weakless_Universe)** > > A weakless universe is a hypothetical universe that contains no weak interactions, but is otherwise very similar to our own universe. > In particular, a weakless universe is constructed to have atomic physics and chemistry identical to standard atomic physics and chemistry. The dynamics of a weakless universe includes a period of Big Bang nucleosynthesis, star formation, stars with sufficient fuel to burn for billions of years, stellar nuclear synthesis of heavy elements and also supernovae that d... ---
**Author:** ![Ponch8](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ponch8/32/9883_2.png) [@Ponch8](https://boards.straightdope.com/u/Ponch8)\ **Post date:** [November 9, 2008, 3:57am UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/10 "2008-11-09T03:57:23Z")
According to the webelements website, even arsenic is an essential element. ---
**Author:** ![FatBaldGuy](https://avatars.discourse-cdn.com/v4/letter/f/ecd19e/32.png) [@FatBaldGuy](https://boards.straightdope.com/u/FatBaldGuy)\ **Post date:** [November 9, 2008, 5:25am UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/11 "2008-11-09T05:25:02Z")
The ancients got by with only four elements–earth, air, fire and water. ---
**Author:** ![KGS](https://avatars.discourse-cdn.com/v4/letter/k/90ced4/32.png) [@KGS](https://boards.straightdope.com/u/KGS)\ **Post date:** [November 9, 2008, 5:42am UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/12 "2008-11-09T05:42:09Z")
We can get by without [Technetium](http://www.theodoregray.com/PeriodicTable/Elements/043/index.s7.html) (element 43). In fact, for most of the Earth’s history, it never existed. ---
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [November 9, 2008, 3:37pm UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/13 "2008-11-09T15:37:23Z")
OK, I’m somewhat curious. This will overlap with some stuff already said, of course. Let’s start with the [webelements data](http://www.webelements.com/periodicity/abundance_humans/) on amounts present in humans (use the log abundance table, shaded - trace quantities show up better). That shows some amounts of these elements present in the human body: H Li Be B C N O F Na Mg Al Si P S Cl K Ca V Cr Mn Fe Co Ni Cu Zn As Se Br Rb Sr Zr Mo Cd Sn I Cs Ba Au Pb Ra U Some subset of that list will actually be required. Now, let’s look at the webelements biological data for all those not obviously required, to see which ones we can eliminate: Li (lithium) - seems to have no biological role, medical effect noted. Be (beryllium) - no biological role. B (boron) - possibly required as an ultratrace. required by algae and higher plants. F (flourine) - probably essential, required by molluscs. Al (aluminum) - may be involved in some enzyme actions and required. Si (silicon) - probably essential in plants, and possibly higher mammals. Used structurally by some important lower organisms, and required for growth in rats and chicks. V (vanadium) - essential to sea squirts, trace required in diets of rats and chicks. Co (cobalt) - essential trace element. Ni (nickel) - essential trace element for many species - it doesn’t explicitly say humans. Cu (copper) - essential trace element. As (arsenic) - may be an essential ultratrace. Required for some other species. Se (selenium) - essential trace element. Br (bromine) - may be an essential trace element for red algae, and possibly mammals. Rb (rubidium) - no biological role. Sr (strontium) - no biological role. Zr (zirconium) - no biological role. Mo (molybdenum) - essential trace element Cd (cadmium) - may be neccesary in very small quantities in rats. Sn (tin) - may be neccesary in very small quantities in rats. Cs (caesium) - no biological role. Ba (barium) - no biological role. Au (gold) - no biological role. Pb (lead) - no biological role. Ra (radium) - no biological role. U (uranium) - no biological role. Eliminating the “no biological role” elements, and giving the rest the benefit of the doubt (molybdenum? really?), we are left with: H B C N O F Na Mg Al Si P S Cl K Ca V Cr Mn Fe Co Ni Cu Zn As Se Br Mo Cd Sn I Obviously, some other elements will be required for support of a working ecology in one way or another, but that seems like a stab at the “essential for body functions” list. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [November 9, 2008, 4:10pm UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/14 "2008-11-09T16:10:42Z")
> [@yabob](#): > > (molybdenum? really?) > **[Molybdenum | Linus Pauling Institute](https://lpi.oregonstate.edu/mic/minerals/molybdenum)** > [@](#): > > In humans, molybdenum is known to function as a cofactor for three enzymes: > > ``` > * Sulfite oxidase catalyzes the transformation of sulfite to sulfate, a reaction that is necessary for the metabolism of sulfur-containing amino acids (methionine and cysteine). > * Xanthine oxidase catalyzes the breakdown of nucleotides (precursors to DNA and RNA) to form uric acid, which contributes to the plasma antioxidant capacity of the blood. > * Aldehyde oxidase and xanthine oxidase catalyze hydroxylation reactions that involve a number of different molecules with similar chemical structures. Xanthine oxidase and aldehyde oxidase also play a role in the metabolism of drugs and toxins (3). > > ``` > > Of these three enzymes, only sulfite oxidase is known to be crucial for human health (4). Plus, it’d be a different world if bacteria were unable to fix nitrogen using the [FeMoco](http://www-ssrl.slac.stanford.edu/research/femoco_summary.html) cofactor. ---
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [November 9, 2008, 4:32pm UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/15 "2008-11-09T16:32:27Z")
Yeah, the nitrogen fixing is mentioned in webelements, too. I am surprised at some elements not showing up in trace quantities in the human body in their data. I’m surprised the body doesn’t accumulate measurable trace amounts of mercury, for instance, like it does lead. ---
**Author:** ![scm1001](https://avatars.discourse-cdn.com/v4/letter/s/c4cdca/32.png) [@scm1001](https://boards.straightdope.com/u/scm1001)\ **Post date:** [November 9, 2008, 8:46pm UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/16 "2008-11-09T20:46:41Z")
I suspect that it would be possible to design simple life to use just a few of these, perhaps as low as ten. It would be interesting to know what the smallest set would be. ---
**Author:** ![BertNobbins](https://avatars.discourse-cdn.com/v4/letter/b/3e96dc/32.png) [@BertNobbins](https://boards.straightdope.com/u/BertNobbins)\ **Post date:** [January 29, 2026, 6:51pm UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/17 "2026-01-29T18:51:49Z")
_The noble gases are chemically inert and other than argon are pretty rare anyway. Hard to see how we’d miss them_. I think we might miss helium. Apart from party balloons and cryogenics, it makes up a quarter of the mass of the sun. ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [January 29, 2026, 9:02pm UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/18 "2026-01-29T21:02:22Z")
> [@Markxxx](#): > > what is the minimum number of elements humans would need to have _ **on earth** _ to live. Emphasis added. ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [January 29, 2026, 9:22pm UTC](https://boards.straightdope.com/t/minimum-number-of-elements-we-could-get-by-with/471771/19 "2026-01-29T21:22:52Z")
There are really two separate questions. What elements do humans require and what elements does life require? Just as an example, humans are obviously heavily dependent on iodine. But could life have evolved without it? Most likely. When I was a student I worked in a lab and one of my tasks was growing E. coli. We used a synthetic medium that included, besides H and O, sources of C, Cl, Na and P. If any other elements were needed I don’t recall them. Of course we made no attempt to purify the things we used so it is possible that other elements appeared in traces, but the above list seemed sufficient.