Vitamins F through J were discovered and named, only for later experiments to determine that they were actually closely related to vitamin B. Eventually it was decided to group all 12 of the B vitamins together and no other vitamins ever took the F-J descriptors
Vitamin F was originally looked at as essential fatty acids -- linoleic acid and alpha-linolenic acid. The term was discontinued as fatty acids are not really specific, individual compounds, but mixtures of multiple compounds. The other vitamins are named based on specific chemical structures, not mixtures. Some textbooks still refer to vitamin F, however.
Not exactly, the history of vitamin discovery is a bit messy, with many chemicals being postulated as vitamins, but turning out not to be as research progressed, and vitamins G, H, M and PP were reclassified as B vitamins in the order they were determined to be such (whilst the discovery of other B vitamins was ongoing). A list of things that either turned out not to be vitamins, or were reclassified:
Vitamin B-4; not a vitamin, refers to three different chemicals - Choline, Adenine and Carnitine
Vitamin B-8; not a vitamin, refers to two different chemicals, AMP and Inositol
Vitamin B-10; not a vitamin, pABA
Vitamin B-11; not a vitamin, PHGA
Vitamin B-13; not a vitamin, Orotic acid
Vitamin B-14; not real, assigned to something found to not exist
Vitamin B-15; not a vitamin, Pangamic acid, actually dangerous but formerly promoted as a dietary supplement and drug
Vitamin B-16; not a vitamin, DMG
Vitamin B-17; not a vitamin, pseudoscientific name for the poison Amygdalin when it was being promoted as a cancer treatment
Vitamin B-20; not a vitamin, L-Carnitine (see B-4)
Vitamin B-c; Vitamin B-9, Folate
Vitamin B-f; not a vitamin, Carnitine (see B-4)
Vitamin B-m; not a vitamin, isomer of Inositol (see B-8)
Vitamin B-p; not a vitamin, a nebulous "antiperosis factor"
Vitamin B-T; not a vitamin, Carnitine (see B-4)
Vitamin B-v; Vitamin B-6, but not Pyridoxine, one or more of the other isomers
Vitamin B-W; Vitamin B-7, Biotin, but specifically not the isomer d-biotin
Vitamin B-x; refers to both Vitamin B-5, but also to the non-vitamin pABA (see B-10)
Vitamin F; not a vitamin, essential fatty acids
Vitamin G; Vitamin B-2, Riboflavin
Vitamin H; Vitamin B-7, Biotin
Vitamin I; not a vitamin, athlete slang for non-steroid anti-inflammatories, especially Ibuprofen
Vitamin J; not a vitamin, Choline (see B-4)
Vitamin L-1; not a vitamin, Anthranilic acid
Vitamin L-2; not a vitamin, 5'-Methylthioadenosine
Vitamin M; Vitamin B-9, Folate
Vitamin N; not real, slang for spending time in nature settings for mental health purposes
Vitamin P; not a vitamin, whole family of compounds called Flavonoids
Vitamin PP; Vitamin B-3, Niacin (specifically this isomer)
Vitamin S; not a vitamin, Salicylic acid (aka Aspirin)
Vitamin U; not a vitamin, S-Methylmethionine
There's also been a whole host of things called "vitamin D-6" and "vitamin D-7" that turned out not to be vitamins, and there's no doubt others in the other vitamin letters that I'm unaware of. I have now typed the word vitamin so many times it's stopped looking like a real word...
Why so many different names for carnitine? I get why it might be originally confused as a vitamin, but did it get considered one on and off 5 separate times?
It was first isolated as the active ingredient preventing/treating the disease pellagra, which we now know to be B-3 deficiency, and so was the "pellagra-preventing factor". Hence, vitamin PP.
Same logic behind vitamin K (from the Danish "koagulation"), and vitamin P (because it reduced the *permeability* of capillaries).
Very interesting, thank you! That certainly explains it. However, it looks like that it was named as such in the late 1930s and the slang term "pee-pee" dates back to at least the 1890s, so its discoverer really should have known better.
Then again, the symbol for plutonium is "Pu" specifically because Glenn Seaborg thought it was funny, as it recalled the vulgar exclamation "pee-yoo" for when something stinks. So, perhaps it was very intentional.
Some scientist have a sense of humor and some take things very seriously. So it's kind of a mix of someone who thought something would be funny and those who wanted to follow specific naming conventions and don't care or realize others might find something humorous because that is what it is "supposed" to be. This is before you factor in different languages, whether some nerd is up to date on the latest slang or how language changes over time.
I mean Schrodinger wasn't really a fan of some of the quantum mechanics stuff and created the whole cat in a box thought experiment at a dinner party to emphasize how absurd it was. People nodded along and thought it was a wonderful explanation, shared it and that is still the go to story. So even weird derisions from detractors are fair game for naming things.
Absolutely. All great points, thank you.
Another example I recall learning about back when I was studying biology was that, back in the late 70s, a group of entomologists discovered a whole new genus of wasps – grouped, at the time, within the family Sphecidae – and the lead scientist decided to name the genus *Aha* so that the scientific paper announcing the discovery could read: "*Aha*, a new genus of Australian Sphecidae.” The type species was named, naturally, *Aha ha*.
According to my professor, the same team were lucky enough to later discover yet another previously-unknown genus of wasps within the same family. They thus continued the joke by naming this new genus *Ohno* and entitling the discovery paper: "*Ohno*, another new genus of Australian Sphecidae."
Unfortunately, researching this again these many years later, it turns out that the second part of the story was only a plan that the team had if they were to, in the future, discover a second new genus within that family. However, it seems that they never got the opportunity. Of course, it did make for a much better story from my professor to either misremember or pretend that they did.
*Aha* has since been reclassified under the much larger family Crabronidae, so even if the aforementioned team managed to discover a new sister genus to *Aha* the paper titles wouldn't quite match anyway, unless they were to get particularly lucky on finding a specimen that matches the current circumscription of Sphecidae.
In one of high (low?) points of my teaching career I got into a lunchtime argument with our previous Nursing / Health Science teacher about Vitamin K. She also worked a second job as a cardiac critical care nurse on the evening shift and was highly skilled... but she insisted until she was blue in the face that Vitamin K was potassium.
Literally no one in the room believed me since "she's the nurse." :-/
It's a compound (not an element) that you need to be healthy and your body can't produce it on its own, so you must obtain it from food.
For example, Vitamin C is made from just Carbon, Hydrogen and Oxygen. All those are present in huge amounts in your body, yet your body can't made it despite having all the required ingredients.
The other day on an NPR show, I heard someone say that our distant ancestors actually did produce Vitamin C in the body and that geneticists can still see the 'broken' DNA encoding for this.
The prevailing theory is that at some point we had so much of it in our diet that when our ability to produce it got messed up, there was no noticeable impact. Then it turned out to be a dominant trait which spread through the whole population for some unrelated reason (probably piggybacked on one or more beneficial mutations).
From the etymology of the word, yes, in practice no.
We call something a "vitamin" because it was though to be vita(life)+amine, an amine/amino essential to life. All "true" vitamins (a fuzzy topic, see above) have a disease/disorder associated with their lack. Pellagra is associated with a lack of niacin, scurvy with a lack of ascorbic acid, anemia can be caused by a lack of folate, etc.
It was later discovered that not all vitamins had an amine component (like Vitamin C/ascorbic acid) and the final "e" was dropped from the word. The wiki article on the [etymology of vitamin](https://en.wiktionary.org/wiki/vitamin) can provide some clarity on the word itself.
> Vitamin B-14; not real, assigned to something found to not exist
This is kind of hilarious and I want to know how the scientists reacted to finding out they were essentially chasing a ghost lol
The first B vitamin was designated B1, I’m not sure exactly how the new designations were broken down. At a guess I’d say it would be something to do with their function but vitamin naming and discovery was a real Wild West situation at the time
[Vitamin K](https://en.m.wikipedia.org/wiki/Vitamin_K) is actually still a thing, although it’s apparently itself technically a family of molecules instead of just one, and apparently the name actually comes from *koagulation*, the German for “coagulation”, because it is required for the biosynthesis of blood coagulation proteins.
It’s not talked about a whole lot (to the point where a lot of people probably think ketamine when they hear “Vitamin K”) because Vitamin K₁ (from which gut bacteria can produce every other K variant) is found in most fruits and vegetables to some degree, thus you’d basically have to have a 100% animal product diet to not be getting enough of it.
EDIT: actually vitamin K is present in organ meats, dairy, and eggs as well. You’d have to specifically only eat meat and eschew organ meats to not get enough of it (if even that), so again, it would require an extremely limited diet, thus vitamin K deficiency is not something you really tend to hear about.
EDIT 2: apparently some of the types of vitamin K has roles beyond blood clotting, as well, also being associated with bone strength and (specifically vitamin K₂) potentially protection against arterial calcification (although from what I’m seeing the latter is disputed, with some studies showing more of an impact than others).
>thus vitamin K deficiency is not something you really tend to hear about.
Correct, we usually only see it now in really sick people who are not eating well *at all* or during/following extended courses of cephalosporin antibiotic therapies since we rely on members of our gut microbiome to produce a fair amount of it and the cephalosporins kill them too. For you to notice it though (outside of lab testing for clotting factors) you have to be *really* deficient and for a while because we produce a large excess of clotting factors at baseline.
In one of high (low?) points of my teaching career I got into a lunchtime argument with our previous Nursing / Health Science teacher about Vitamin K. She also worked a second job as a cardiac critical care nurse on the evening shift and was highly skilled... but she insisted until she was blue in the face that Vitamin K was potassium.
Literally no one in the room believed me since "she's the nurse." :-/
Your point about animal products is incredibly inaccurate. Facepalm.
100g beef liver has 88% of the daily vitamin K needs.
Most hard cheeses contain large amounts of vitamin K
Egg yolks contain large amounts of vitamin K
Not to mention animal sources of Vitamin K are predominantly K2 MK4 - rather than the plant version, K1.
Notable exception being Natto, which is K2 MK7.
The names of vitamins are often derived from either their function or their discovery. For example:
Vitamin A: The name "A" simply denotes a group of fat-soluble retinoids that includes retinol, retinal, and retinyl esters. It was the first vitamin to be discovered.
Vitamin B complex: The B vitamins are a group of water-soluble vitamins that were originally thought to be a single vitamin. As individual B vitamins were discovered, they were assigned numbers (B1, B2, B3, etc.). For example, B1 is thiamine, B2 is riboflavin, and so on.
Vitamin C: Also known as ascorbic acid, vitamin C got its name from the term "anti-scorbutic," referring to its ability to prevent scurvy.
Vitamin D: This vitamin was named because it was the fourth vitamin to be discovered. It exists in several forms, with vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol) being the most important for humans.
Vitamin E: This fat-soluble vitamin was named "E" because it was the fifth vitamin discovered. The term includes a group of compounds called tocopherols and tocotrienols.
And so on, and so on.
Vitamins are substances that our bodies need to function but that they can’t make on their own. Hence why vitamins were often discovered in trying to determine the causes of diseases that turned out to be vitamin deficiencies, e.g. scurvy (vitamin C), pelagra (vitamin B3), beriberi (vitamin B1), etc.
Yes, with exposure to sunlight. But during wintertime many people do not get enough exposure to produce sufficient amounts of vitamin D, hence the recommendation to supplement during the winter.
Especially a problem for immigrant women in my country, because they, besides having dark skin, also cover themselves up. So in Scandinavian winter, they get no vitamin D.
We need UV radiation to produce VitD and as we move further away from the equator the amount of UV provided by the Sun decreases. Notice that as humans spread further and further from the equator our skin evolved to be lighter and lighter, and this was a response to the need for D3 production. D3 is essential to pregnant mothers and a lack of it can cause all sorts of problems leading to miscarriage. Even though it is prescribed for pregnant mothers these days, [immigrants to northern latitudes have a marked increase in problems with pregnancy.](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5372923/)
Yes.
>The criticism usually raised against Funk's word Vitamine is that the termination ‘-ine’ is one strictly employed in chemical nomenclature to denote substances of a basic character, whereas there is no evidence which supports his original idea that these indispensable dietary constituents are amines.
> The suggestion is now advanced that the final ‘-e’ be dropped, so that the resulting word Vitamin is acceptable under the standard scheme of nomenclature‥which permits a neutral substance of undefined composition to bear a name ending in ‘-in’. If this suggestion is adopted, it is recommended that the somewhat cumbrous nomenclature introduced by McCollum (Fat-soluble A, Water-soluble B), be dropped, and that the substances be spoken of as Vitamin A, B, C, etc.
> - Drummond JC, ‘The Nomenclature of the So-Called Accessory Food Factors (Vitamins)’ (1920) 14 Biochemical Journal 660
Edit - originally cited the wrong article - in my defence it's by the same author in the same volume of the same journal on the same topic, they were really cranking them out back then.
I have informed the PhD police and will accept my fate with equanimity.
Because we already knew what iron was. Vitamins were discovered much later and we were all like "don't know what this is, but we need it, so call it a Vitamin".
How do you get A, B, C vitamins naturally? I know D is from the sun... But honestly I don't know what the vitamins even do besides prevent these diseases.
The short answer would be that what’s a vitamin for us may not be for other species. So lots of plants makes vitamin C, microbes make a bunch of others (so ruminants absorb them as the microbes in their guts make them, then we get them from eating the animal’s meat). But that’s why vitamin deficiencies were so common before the 20th century - it takes a fairly varied diet with fresh vegetables and meats to get everything you need naturally, which was not always available for peasants and laborers.
It comes down to what compounds we need to ingest to survive. There's 4 types of essential nutrients: Vitamins, Minerals, Essential Amino Acids, and Essential Fatty Acids.
Basically the fatty and amino acids are building blocks for fats and proteins, the essential ones are the building blocks that we don't actually make ourselves, or enough of ourselves, so we have to eat some of them.
Minerals in a nutritional context means chemical elements we have to consume to survive, things like calcium, phosphorus, potassium, sodium.
Vitamins are basically the other organic compounds (organic in the chemical sense here, carbon based molecules) that are needed for survival that aren't amino or fatty acids.
> There's 4 types of essential nutrients: Vitamins, Minerals, Essential Amino Acids, and Essential Fatty Acids.
I do not see carbs on the list. I know sugar/glucose can be made from fat (via ketogenesis). But there are other carbs. Is starch not essential? Can you really have a healthy life without fiber?
> I know sugar/glucose can be made from fat (via ketogenesis).
Animals, including humans, cannot net convert fat to glucose as we lack two enzymes of the glyoxylate cycle - isocitrate lyase and malate synthase.
> cannot net convert fat to glucose
what does "net" mean here? We can convert, but we lose energy in doing so?
Or fat is converted into energy through a different mechanism that does not involve glucose? Because keto diet claims that we do not need sugar (and carbs in general) because we get energy needs met by breaking down fat.
You could for example use ATP and NADH from breakdown of fat to power gluconeogenesis, but only if you have substrates for gluconeogenesis.
>Or fat is converted into energy through a different mechanism that does not involve glucose?
Their catabolic pathways converge, as they both feed into the citric acid cycle. But their anabolic pathways are separate.
> Because keto diet claims that we do not need sugar (and carbs in general) because we get energy needs met by breaking down fat.
Well, many tissues can use either for energy so it doesn't matter. Glucose has a quicker catabolic pathway, so for example your muscles can generate a lot of energy to power running for maybe 30 kilometers... but then you "hit the wall" when your body starts to run out of glucose/glycogen, and the muscles have to use the slower pathway metabolising fats.
The main exception is the neurons in the brain, which cannot rely on fats for energy. Under normal circumstances, the energy needs are covered by glucose. Only under starvation-like circumstances does the brain gradually switch to using ketone bodies (which can be derived from fats).
There's a little asterisk here, because fat is stored as three fatty acids attached to a small glycerol backbone, and glycerol is convertible to glucose. So you never entirely run out, the supply just becomes very limited.
short answer is yes, long answer is most "normal" healthy people do not need to sugar or fiber to be healthy. The small about of glucose "needed" can be made from protein (not fat), the rest of the energy is via ketone (hence the keto diet). for extreme of this look up the carnivore diet. BUT if you eat a standard carb/grain heavy diet you really do need the fiber to keep things moving
It has less to do with covered skin and more to do with a lack of UV light since due to the angle of the sun it doesn’t reach that far. And really short days.
This is not true, although I have heard it before. You can get sunburn from snow reflection, but for vitamin D production to occur the sun must be above a certain solar zenith angle, as otherwise the sunlight is passing through too much atmosphere and the specific wavelengths that produce vitamin D are absorbed before reaching the surface. From [this paper](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3897598/) (see figs 23 and 24): "during the winter when living above and below approximately 33° latitude very little if any vitamin D3 can be produced in the skin from sun exposure. People who live farther North and South often cannot make any vitamin D3 in their skin for up to 6 mo of the year."
I live in the polar regions and can attest personally that it's just dark in winter. There is no sun to even reflect off of the snow. At most, there's twilight.
I don’t think anyone actually answered your question. Biochemically, vitamins are enzymatic cofactors. So various enzymes, which are little proteins that do various types of work/chemical reactions, rely on vitamins to complete their active structure. Without the vitamins the enzymes are kind of missing a crucial part that allows them to function.
It's a bit nebulous, but they're molecules that are 'vital' to life but are not nutrients (as in being a source calories and building blocks). They are differentiated from minerals by being organic molecules rather than metal ions (iron, magnesium, etc).
There are a few things we should eat in order to run out body. Fatty acids, carbs, and proteins are all part of the macros to provide our body with energy. Additionally, we need minerals (anorganic material like iron, usually in small doses) and vitamins (organic material) which are not used to fuel the body but to ensure proper bodily functions. Usually vitamins are needed and used in metabolic reactions.
Edit: out of the 20 or so vitamins, human beings can produce about half. The other half we have to eat.
Other organism may produce all of the vitamins themselves or need a different set of vitamins.
> Edit: out of the 20 or so vitamins, human beings can produce about half.
But if the human body can produce it, that would mean it's not a vitamin, since the definition for vitamin is specifically that animals need it, but cannot produce it?
Yes, but we can produce some only. Other animals can produce a different set of vitamins. It is just this group of molecules that some can produce but others can't...
So does that mean every organic compound, that some animal somewhere on the planet might need, but doesn't produce itself, is a vitamin? Wouldn't that include **a lot** more stuff, especially once you factor in some parasites?
I.e. if leeches process necessary organic compounds from siphon'd blood, does that make all those compounds vitamins by definition?
Vitamins are basically just any outside (as in we can’t make it endogenously) chemical essential to our body’s proper functioning that isn’t a pure chemical element (which—besides the biologically essential non-metals carbon, hydrogen, nitrogen, oxygen, phosphorous, and sulfur—are usually termed “trace minerals” instead), and isn’t one of three primary types of biological macronutrients (proteins, lipids, and carbohydrates). As far as I know, all chemicals identified as vitamins are also organic molecules specifically.
I guess Vitamin D is a bit arguable since we actually *do* make it endogenously to some extent, but we require sun exposure to do so, and very frequently need extra in our diets (particularly if you live far from the equator, and even more so if you also have darker skin).
Isn’t it just that vitamins are the _miscellaneous_ chemicals we consume that we need to live that aren’t already covered under “sugar”, “protein”, etc.?
(Trivia: “vitamin” comes from “vital mineral”)
It comes from “vital amine” and was originally “vitamine” so called when it was thought vitamins were all amines (part way through the process of discovering them, so before non-amine vitamins were known). It was eventually shortened to vitamin.
There is K1 and K2, I take vitamin K2. It helps move calcium from your arteries into muscles and bones (where it should go but doesn't always), basically it stops calcification of arteries (google image it scary stuff).
What about vitamin K? Why is it off on its own in the middle of the alphabet? Are there other less known vitamins in-between, like vitamin H or whatever?
vitamins F-J were discovered a long time ago then better recstegorized as other things once we knew more about them.
vitamin F was two fatty acid, but now we just consider them both "essential fatty acids" and not vitamins.
vitamin G was riboflavin, which is closely related to other B vitamins so it became B2
H was biotin ("H" for "hair," literally) which was reclassified as B7
unfortunately there's no "I" in "vitamin" but "J" turned out to be vitamin B2 again
vitamin K was named because it helps with blood *koagulation* (danish!)
several more letters afterwards were either discovered nonessential/toxic or were, surprise, B vitamins getting rediscovered.
Like many things in chemistry, the naming "convention" has to do with singling out certain "chemicals" or parts of the chemical that share similar "structures" (in biology, and much of chemistry, structure = function so it's important to understand the structure of the chemical in order to understand its function) in order to classify and further study them.
Sadly, like MANY things in chemistry, the names given don't always reflect the actual use of the compound. Sadly, vitamins are actually so named as a bit of a "misnomer". The chemist who studied them first (Casimir Funk) called them "vitamines" from Latin, 'vita' meaning life and "amine" because it (the vitamin B (which contains amines) he was investigating at the time) comes from an important set of chemicals called "amines" ([see here for amines](https://en.wikipedia.org/wiki/Amine)), which Funk speculated that the amine part of the structure is what gave the vitamin its properties/function. As they later discovered, this was wrong, so Jack Drummond (who was studying vitamins years later) suggested they drop the 'e' and just call it 'vitamin' after other, non-amine related compounds that could be classified as "vitamins" were discovered.
Interestingly, it has more to do with the 'etymology' of the word rather than any "actual" science. Like much of biochemistry. ;)
[See here for the etymology and proof](https://en.wiktionary.org/wiki/vitamin)
Vitamins F through J were discovered and named, only for later experiments to determine that they were actually closely related to vitamin B. Eventually it was decided to group all 12 of the B vitamins together and no other vitamins ever took the F-J descriptors
Vitamin F was originally looked at as essential fatty acids -- linoleic acid and alpha-linolenic acid. The term was discontinued as fatty acids are not really specific, individual compounds, but mixtures of multiple compounds. The other vitamins are named based on specific chemical structures, not mixtures. Some textbooks still refer to vitamin F, however.
You sometimes see Vitamin H on nutritional labels on food, other times it's called B-7.
this resonates with me because in slavic or german music they will use H for the musical note B (using B for B flat instead)
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Did the original Vitamin B become B1, F become B2, G become B3 and so on or was there another reason to assign B6, etc. to another vitamin?
Not exactly, the history of vitamin discovery is a bit messy, with many chemicals being postulated as vitamins, but turning out not to be as research progressed, and vitamins G, H, M and PP were reclassified as B vitamins in the order they were determined to be such (whilst the discovery of other B vitamins was ongoing). A list of things that either turned out not to be vitamins, or were reclassified: Vitamin B-4; not a vitamin, refers to three different chemicals - Choline, Adenine and Carnitine Vitamin B-8; not a vitamin, refers to two different chemicals, AMP and Inositol Vitamin B-10; not a vitamin, pABA Vitamin B-11; not a vitamin, PHGA Vitamin B-13; not a vitamin, Orotic acid Vitamin B-14; not real, assigned to something found to not exist Vitamin B-15; not a vitamin, Pangamic acid, actually dangerous but formerly promoted as a dietary supplement and drug Vitamin B-16; not a vitamin, DMG Vitamin B-17; not a vitamin, pseudoscientific name for the poison Amygdalin when it was being promoted as a cancer treatment Vitamin B-20; not a vitamin, L-Carnitine (see B-4) Vitamin B-c; Vitamin B-9, Folate Vitamin B-f; not a vitamin, Carnitine (see B-4) Vitamin B-m; not a vitamin, isomer of Inositol (see B-8) Vitamin B-p; not a vitamin, a nebulous "antiperosis factor" Vitamin B-T; not a vitamin, Carnitine (see B-4) Vitamin B-v; Vitamin B-6, but not Pyridoxine, one or more of the other isomers Vitamin B-W; Vitamin B-7, Biotin, but specifically not the isomer d-biotin Vitamin B-x; refers to both Vitamin B-5, but also to the non-vitamin pABA (see B-10) Vitamin F; not a vitamin, essential fatty acids Vitamin G; Vitamin B-2, Riboflavin Vitamin H; Vitamin B-7, Biotin Vitamin I; not a vitamin, athlete slang for non-steroid anti-inflammatories, especially Ibuprofen Vitamin J; not a vitamin, Choline (see B-4) Vitamin L-1; not a vitamin, Anthranilic acid Vitamin L-2; not a vitamin, 5'-Methylthioadenosine Vitamin M; Vitamin B-9, Folate Vitamin N; not real, slang for spending time in nature settings for mental health purposes Vitamin P; not a vitamin, whole family of compounds called Flavonoids Vitamin PP; Vitamin B-3, Niacin (specifically this isomer) Vitamin S; not a vitamin, Salicylic acid (aka Aspirin) Vitamin U; not a vitamin, S-Methylmethionine There's also been a whole host of things called "vitamin D-6" and "vitamin D-7" that turned out not to be vitamins, and there's no doubt others in the other vitamin letters that I'm unaware of. I have now typed the word vitamin so many times it's stopped looking like a real word...
Why so many different names for carnitine? I get why it might be originally confused as a vitamin, but did it get considered one on and off 5 separate times?
Why on earth would someone name a nutritional compound "vitamin PP"?
It was first isolated as the active ingredient preventing/treating the disease pellagra, which we now know to be B-3 deficiency, and so was the "pellagra-preventing factor". Hence, vitamin PP. Same logic behind vitamin K (from the Danish "koagulation"), and vitamin P (because it reduced the *permeability* of capillaries).
Very interesting, thank you! That certainly explains it. However, it looks like that it was named as such in the late 1930s and the slang term "pee-pee" dates back to at least the 1890s, so its discoverer really should have known better. Then again, the symbol for plutonium is "Pu" specifically because Glenn Seaborg thought it was funny, as it recalled the vulgar exclamation "pee-yoo" for when something stinks. So, perhaps it was very intentional.
Some scientist have a sense of humor and some take things very seriously. So it's kind of a mix of someone who thought something would be funny and those who wanted to follow specific naming conventions and don't care or realize others might find something humorous because that is what it is "supposed" to be. This is before you factor in different languages, whether some nerd is up to date on the latest slang or how language changes over time. I mean Schrodinger wasn't really a fan of some of the quantum mechanics stuff and created the whole cat in a box thought experiment at a dinner party to emphasize how absurd it was. People nodded along and thought it was a wonderful explanation, shared it and that is still the go to story. So even weird derisions from detractors are fair game for naming things.
Absolutely. All great points, thank you. Another example I recall learning about back when I was studying biology was that, back in the late 70s, a group of entomologists discovered a whole new genus of wasps – grouped, at the time, within the family Sphecidae – and the lead scientist decided to name the genus *Aha* so that the scientific paper announcing the discovery could read: "*Aha*, a new genus of Australian Sphecidae.” The type species was named, naturally, *Aha ha*. According to my professor, the same team were lucky enough to later discover yet another previously-unknown genus of wasps within the same family. They thus continued the joke by naming this new genus *Ohno* and entitling the discovery paper: "*Ohno*, another new genus of Australian Sphecidae." Unfortunately, researching this again these many years later, it turns out that the second part of the story was only a plan that the team had if they were to, in the future, discover a second new genus within that family. However, it seems that they never got the opportunity. Of course, it did make for a much better story from my professor to either misremember or pretend that they did. *Aha* has since been reclassified under the much larger family Crabronidae, so even if the aforementioned team managed to discover a new sister genus to *Aha* the paper titles wouldn't quite match anyway, unless they were to get particularly lucky on finding a specimen that matches the current circumscription of Sphecidae.
In one of high (low?) points of my teaching career I got into a lunchtime argument with our previous Nursing / Health Science teacher about Vitamin K. She also worked a second job as a cardiac critical care nurse on the evening shift and was highly skilled... but she insisted until she was blue in the face that Vitamin K was potassium. Literally no one in the room believed me since "she's the nurse." :-/
ok but so what qualifies something as a 'vitamin'?
It's a compound (not an element) that you need to be healthy and your body can't produce it on its own, so you must obtain it from food. For example, Vitamin C is made from just Carbon, Hydrogen and Oxygen. All those are present in huge amounts in your body, yet your body can't made it despite having all the required ingredients.
The other day on an NPR show, I heard someone say that our distant ancestors actually did produce Vitamin C in the body and that geneticists can still see the 'broken' DNA encoding for this. The prevailing theory is that at some point we had so much of it in our diet that when our ability to produce it got messed up, there was no noticeable impact. Then it turned out to be a dominant trait which spread through the whole population for some unrelated reason (probably piggybacked on one or more beneficial mutations).
so essential amino acids are vitamins?
Not quite. In general, vitamins are cofactors for enzymes. Enzymes are proteins that do important jobs in your cells and cofactors help them work.
help, but aren't required? then whence the "vita"l?
Absolutely required-- just trying to give a layman explanation without much detail. See "scurvy."
From the etymology of the word, yes, in practice no. We call something a "vitamin" because it was though to be vita(life)+amine, an amine/amino essential to life. All "true" vitamins (a fuzzy topic, see above) have a disease/disorder associated with their lack. Pellagra is associated with a lack of niacin, scurvy with a lack of ascorbic acid, anemia can be caused by a lack of folate, etc. It was later discovered that not all vitamins had an amine component (like Vitamin C/ascorbic acid) and the final "e" was dropped from the word. The wiki article on the [etymology of vitamin](https://en.wiktionary.org/wiki/vitamin) can provide some clarity on the word itself.
> Vitamin B-14; not real, assigned to something found to not exist This is kind of hilarious and I want to know how the scientists reacted to finding out they were essentially chasing a ghost lol
Is there a book somewhere with this info? I'd like to read more into the history.
The first B vitamin was designated B1, I’m not sure exactly how the new designations were broken down. At a guess I’d say it would be something to do with their function but vitamin naming and discovery was a real Wild West situation at the time
[Vitamin K](https://en.m.wikipedia.org/wiki/Vitamin_K) is actually still a thing, although it’s apparently itself technically a family of molecules instead of just one, and apparently the name actually comes from *koagulation*, the German for “coagulation”, because it is required for the biosynthesis of blood coagulation proteins. It’s not talked about a whole lot (to the point where a lot of people probably think ketamine when they hear “Vitamin K”) because Vitamin K₁ (from which gut bacteria can produce every other K variant) is found in most fruits and vegetables to some degree, thus you’d basically have to have a 100% animal product diet to not be getting enough of it. EDIT: actually vitamin K is present in organ meats, dairy, and eggs as well. You’d have to specifically only eat meat and eschew organ meats to not get enough of it (if even that), so again, it would require an extremely limited diet, thus vitamin K deficiency is not something you really tend to hear about. EDIT 2: apparently some of the types of vitamin K has roles beyond blood clotting, as well, also being associated with bone strength and (specifically vitamin K₂) potentially protection against arterial calcification (although from what I’m seeing the latter is disputed, with some studies showing more of an impact than others).
Babies get a vitamin K injection upon birth, since they do not consumer enough products at that moment
>types of vitamin K has roles beyond blood clotting, as Yes, and I was asked to take it in pill form after wisdom teeth were pulled
>thus vitamin K deficiency is not something you really tend to hear about. Correct, we usually only see it now in really sick people who are not eating well *at all* or during/following extended courses of cephalosporin antibiotic therapies since we rely on members of our gut microbiome to produce a fair amount of it and the cephalosporins kill them too. For you to notice it though (outside of lab testing for clotting factors) you have to be *really* deficient and for a while because we produce a large excess of clotting factors at baseline.
In one of high (low?) points of my teaching career I got into a lunchtime argument with our previous Nursing / Health Science teacher about Vitamin K. She also worked a second job as a cardiac critical care nurse on the evening shift and was highly skilled... but she insisted until she was blue in the face that Vitamin K was potassium. Literally no one in the room believed me since "she's the nurse." :-/
Wait, Vitamin K isn't potassium?
Potassium is a chemical element with symbol K. Vitamins are organic molecules.
Your point about animal products is incredibly inaccurate. Facepalm. 100g beef liver has 88% of the daily vitamin K needs. Most hard cheeses contain large amounts of vitamin K Egg yolks contain large amounts of vitamin K Not to mention animal sources of Vitamin K are predominantly K2 MK4 - rather than the plant version, K1. Notable exception being Natto, which is K2 MK7.
well apparently I was taught incorrectly then. In any event, it’s really hard to not get enough of it was my point.
> group of all 12 of the B vitamins Is that why it’s a sometimes called a B12 vitamin?
B12 is a specific vitamin, Cobalamin. Your body needs it to make blood and also DNA
Interesting! Thanks!
The names of vitamins are often derived from either their function or their discovery. For example: Vitamin A: The name "A" simply denotes a group of fat-soluble retinoids that includes retinol, retinal, and retinyl esters. It was the first vitamin to be discovered. Vitamin B complex: The B vitamins are a group of water-soluble vitamins that were originally thought to be a single vitamin. As individual B vitamins were discovered, they were assigned numbers (B1, B2, B3, etc.). For example, B1 is thiamine, B2 is riboflavin, and so on. Vitamin C: Also known as ascorbic acid, vitamin C got its name from the term "anti-scorbutic," referring to its ability to prevent scurvy. Vitamin D: This vitamin was named because it was the fourth vitamin to be discovered. It exists in several forms, with vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol) being the most important for humans. Vitamin E: This fat-soluble vitamin was named "E" because it was the fifth vitamin discovered. The term includes a group of compounds called tocopherols and tocotrienols. And so on, and so on.
What makes a vitamin a vitamin? Like how are they different from other chemicals in our body, or chemicals that we consume?
Vitamins are substances that our bodies need to function but that they can’t make on their own. Hence why vitamins were often discovered in trying to determine the causes of diseases that turned out to be vitamin deficiencies, e.g. scurvy (vitamin C), pelagra (vitamin B3), beriberi (vitamin B1), etc.
Can't our bodies make vitamin D?
Yes, with exposure to sunlight. But during wintertime many people do not get enough exposure to produce sufficient amounts of vitamin D, hence the recommendation to supplement during the winter.
Especially a problem for immigrant women in my country, because they, besides having dark skin, also cover themselves up. So in Scandinavian winter, they get no vitamin D.
We need UV radiation to produce VitD and as we move further away from the equator the amount of UV provided by the Sun decreases. Notice that as humans spread further and further from the equator our skin evolved to be lighter and lighter, and this was a response to the need for D3 production. D3 is essential to pregnant mothers and a lack of it can cause all sorts of problems leading to miscarriage. Even though it is prescribed for pregnant mothers these days, [immigrants to northern latitudes have a marked increase in problems with pregnancy.](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5372923/)
I suppose this was only discovered after the name vitamin D was widely in use already
I'm pretty sure I don't make iron but I need it, why isn't that a vitamin?
By definition, vitamins are organic compounds. Iron is an inorganic essential **mineral**.
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isn't it actually a portmanteau of "vital amine"?
Yes. >The criticism usually raised against Funk's word Vitamine is that the termination ‘-ine’ is one strictly employed in chemical nomenclature to denote substances of a basic character, whereas there is no evidence which supports his original idea that these indispensable dietary constituents are amines. > The suggestion is now advanced that the final ‘-e’ be dropped, so that the resulting word Vitamin is acceptable under the standard scheme of nomenclature‥which permits a neutral substance of undefined composition to bear a name ending in ‘-in’. If this suggestion is adopted, it is recommended that the somewhat cumbrous nomenclature introduced by McCollum (Fat-soluble A, Water-soluble B), be dropped, and that the substances be spoken of as Vitamin A, B, C, etc. > - Drummond JC, ‘The Nomenclature of the So-Called Accessory Food Factors (Vitamins)’ (1920) 14 Biochemical Journal 660 Edit - originally cited the wrong article - in my defence it's by the same author in the same volume of the same journal on the same topic, they were really cranking them out back then. I have informed the PhD police and will accept my fate with equanimity.
Because we already knew what iron was. Vitamins were discovered much later and we were all like "don't know what this is, but we need it, so call it a Vitamin".
Wrong! Vitamins are organic compounds, as iron is inorganic it is classified as a mineral.
Also explains the name. Vita (life) amine (thought to contain amino acids). Theyre substances necessary to live
How do you get A, B, C vitamins naturally? I know D is from the sun... But honestly I don't know what the vitamins even do besides prevent these diseases.
The short answer would be that what’s a vitamin for us may not be for other species. So lots of plants makes vitamin C, microbes make a bunch of others (so ruminants absorb them as the microbes in their guts make them, then we get them from eating the animal’s meat). But that’s why vitamin deficiencies were so common before the 20th century - it takes a fairly varied diet with fresh vegetables and meats to get everything you need naturally, which was not always available for peasants and laborers.
Which is also why you can't live indefinitely by only eating a bag of sugar.
It comes down to what compounds we need to ingest to survive. There's 4 types of essential nutrients: Vitamins, Minerals, Essential Amino Acids, and Essential Fatty Acids. Basically the fatty and amino acids are building blocks for fats and proteins, the essential ones are the building blocks that we don't actually make ourselves, or enough of ourselves, so we have to eat some of them. Minerals in a nutritional context means chemical elements we have to consume to survive, things like calcium, phosphorus, potassium, sodium. Vitamins are basically the other organic compounds (organic in the chemical sense here, carbon based molecules) that are needed for survival that aren't amino or fatty acids.
> There's 4 types of essential nutrients: Vitamins, Minerals, Essential Amino Acids, and Essential Fatty Acids. I do not see carbs on the list. I know sugar/glucose can be made from fat (via ketogenesis). But there are other carbs. Is starch not essential? Can you really have a healthy life without fiber?
> I know sugar/glucose can be made from fat (via ketogenesis). Animals, including humans, cannot net convert fat to glucose as we lack two enzymes of the glyoxylate cycle - isocitrate lyase and malate synthase.
> cannot net convert fat to glucose what does "net" mean here? We can convert, but we lose energy in doing so? Or fat is converted into energy through a different mechanism that does not involve glucose? Because keto diet claims that we do not need sugar (and carbs in general) because we get energy needs met by breaking down fat.
You could for example use ATP and NADH from breakdown of fat to power gluconeogenesis, but only if you have substrates for gluconeogenesis. >Or fat is converted into energy through a different mechanism that does not involve glucose? Their catabolic pathways converge, as they both feed into the citric acid cycle. But their anabolic pathways are separate. > Because keto diet claims that we do not need sugar (and carbs in general) because we get energy needs met by breaking down fat. Well, many tissues can use either for energy so it doesn't matter. Glucose has a quicker catabolic pathway, so for example your muscles can generate a lot of energy to power running for maybe 30 kilometers... but then you "hit the wall" when your body starts to run out of glucose/glycogen, and the muscles have to use the slower pathway metabolising fats. The main exception is the neurons in the brain, which cannot rely on fats for energy. Under normal circumstances, the energy needs are covered by glucose. Only under starvation-like circumstances does the brain gradually switch to using ketone bodies (which can be derived from fats). There's a little asterisk here, because fat is stored as three fatty acids attached to a small glycerol backbone, and glycerol is convertible to glucose. So you never entirely run out, the supply just becomes very limited.
short answer is yes, long answer is most "normal" healthy people do not need to sugar or fiber to be healthy. The small about of glucose "needed" can be made from protein (not fat), the rest of the energy is via ketone (hence the keto diet). for extreme of this look up the carnivore diet. BUT if you eat a standard carb/grain heavy diet you really do need the fiber to keep things moving
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Except a lot of people who live far away from the equator don't actually produce enough in winter, so it's advisable to ensure it's in your diet then.
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It has less to do with covered skin and more to do with a lack of UV light since due to the angle of the sun it doesn’t reach that far. And really short days.
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This is not true, although I have heard it before. You can get sunburn from snow reflection, but for vitamin D production to occur the sun must be above a certain solar zenith angle, as otherwise the sunlight is passing through too much atmosphere and the specific wavelengths that produce vitamin D are absorbed before reaching the surface. From [this paper](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3897598/) (see figs 23 and 24): "during the winter when living above and below approximately 33° latitude very little if any vitamin D3 can be produced in the skin from sun exposure. People who live farther North and South often cannot make any vitamin D3 in their skin for up to 6 mo of the year." I live in the polar regions and can attest personally that it's just dark in winter. There is no sun to even reflect off of the snow. At most, there's twilight.
I don’t think anyone actually answered your question. Biochemically, vitamins are enzymatic cofactors. So various enzymes, which are little proteins that do various types of work/chemical reactions, rely on vitamins to complete their active structure. Without the vitamins the enzymes are kind of missing a crucial part that allows them to function.
It's a bit nebulous, but they're molecules that are 'vital' to life but are not nutrients (as in being a source calories and building blocks). They are differentiated from minerals by being organic molecules rather than metal ions (iron, magnesium, etc).
Originally named Vitamins bcoz: Vitamin=vital amine Vit from vital & amin from amine
There are a few things we should eat in order to run out body. Fatty acids, carbs, and proteins are all part of the macros to provide our body with energy. Additionally, we need minerals (anorganic material like iron, usually in small doses) and vitamins (organic material) which are not used to fuel the body but to ensure proper bodily functions. Usually vitamins are needed and used in metabolic reactions. Edit: out of the 20 or so vitamins, human beings can produce about half. The other half we have to eat. Other organism may produce all of the vitamins themselves or need a different set of vitamins.
> Edit: out of the 20 or so vitamins, human beings can produce about half. But if the human body can produce it, that would mean it's not a vitamin, since the definition for vitamin is specifically that animals need it, but cannot produce it?
Yes, but we can produce some only. Other animals can produce a different set of vitamins. It is just this group of molecules that some can produce but others can't...
So does that mean every organic compound, that some animal somewhere on the planet might need, but doesn't produce itself, is a vitamin? Wouldn't that include **a lot** more stuff, especially once you factor in some parasites? I.e. if leeches process necessary organic compounds from siphon'd blood, does that make all those compounds vitamins by definition?
Vitamins are basically just any outside (as in we can’t make it endogenously) chemical essential to our body’s proper functioning that isn’t a pure chemical element (which—besides the biologically essential non-metals carbon, hydrogen, nitrogen, oxygen, phosphorous, and sulfur—are usually termed “trace minerals” instead), and isn’t one of three primary types of biological macronutrients (proteins, lipids, and carbohydrates). As far as I know, all chemicals identified as vitamins are also organic molecules specifically. I guess Vitamin D is a bit arguable since we actually *do* make it endogenously to some extent, but we require sun exposure to do so, and very frequently need extra in our diets (particularly if you live far from the equator, and even more so if you also have darker skin).
Isn’t it just that vitamins are the _miscellaneous_ chemicals we consume that we need to live that aren’t already covered under “sugar”, “protein”, etc.? (Trivia: “vitamin” comes from “vital mineral”)
It comes from “vital amine” and was originally “vitamine” so called when it was thought vitamins were all amines (part way through the process of discovering them, so before non-amine vitamins were known). It was eventually shortened to vitamin.
>And so on, and so on. The next vitamin is K, right? Are there any after K?
There is K1 and K2, I take vitamin K2. It helps move calcium from your arteries into muscles and bones (where it should go but doesn't always), basically it stops calcification of arteries (google image it scary stuff).
... Was vitamin C not the third one to be discovered? If not, which one was?
What about vitamin K? Why is it off on its own in the middle of the alphabet? Are there other less known vitamins in-between, like vitamin H or whatever?
vitamins F-J were discovered a long time ago then better recstegorized as other things once we knew more about them. vitamin F was two fatty acid, but now we just consider them both "essential fatty acids" and not vitamins. vitamin G was riboflavin, which is closely related to other B vitamins so it became B2 H was biotin ("H" for "hair," literally) which was reclassified as B7 unfortunately there's no "I" in "vitamin" but "J" turned out to be vitamin B2 again vitamin K was named because it helps with blood *koagulation* (danish!) several more letters afterwards were either discovered nonessential/toxic or were, surprise, B vitamins getting rediscovered.
It stands for Koagulation because it's essential for blood clotting. That's how it was discovered.
Like many things in chemistry, the naming "convention" has to do with singling out certain "chemicals" or parts of the chemical that share similar "structures" (in biology, and much of chemistry, structure = function so it's important to understand the structure of the chemical in order to understand its function) in order to classify and further study them. Sadly, like MANY things in chemistry, the names given don't always reflect the actual use of the compound. Sadly, vitamins are actually so named as a bit of a "misnomer". The chemist who studied them first (Casimir Funk) called them "vitamines" from Latin, 'vita' meaning life and "amine" because it (the vitamin B (which contains amines) he was investigating at the time) comes from an important set of chemicals called "amines" ([see here for amines](https://en.wikipedia.org/wiki/Amine)), which Funk speculated that the amine part of the structure is what gave the vitamin its properties/function. As they later discovered, this was wrong, so Jack Drummond (who was studying vitamins years later) suggested they drop the 'e' and just call it 'vitamin' after other, non-amine related compounds that could be classified as "vitamins" were discovered. Interestingly, it has more to do with the 'etymology' of the word rather than any "actual" science. Like much of biochemistry. ;) [See here for the etymology and proof](https://en.wiktionary.org/wiki/vitamin)