Eli5: [ELI5] What qualifies a chemical or mineral as a “vitamin?” Are all vitamins good for you in proper dosages?

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Eli5: [ELI5] What qualifies a chemical or mineral as a “vitamin?” Are all vitamins good for you in proper dosages?

In: Biology

There are 13 essential vitamins — vitamins A, C, D, E, K, and the B vitamins (thiamine, riboflavin, niacin, pantothenic acid, biotin, B6, B12, and folate). Too much or not enough of any of them can have an effect on your health. In general, too much is hard to accomplish (but you could manage it if you really tried I guess). Depending on what vitamin you are deficient in, it can have different effects.

A vitamin is an essential nutrient that can’t be synthesized in the body and must be obtained through diet. So anything you need but can’t make yourself is a vitamin. And for example while we need Vitamin C, there are some organisms that can make their own so in their case it’s not a vitamin.

The word was originally “vitamine” in 1920 mean to refer to chemicals thought to contain amino acids necessary for the function of living organisms. This was changed to “vitamin” when we learned that amino acids were not necessarily a component of these substances.

Generally, a vitamin has the following properties:

* It is an organic molecule (That is a molecule built around the element carbon with carbon-hydrogen bonds)
* It is an essential nutrient (It plays a part in the biochemical processes that keep your body alive and help sustain it and allow it to grow and function)

In contrast we have things like fatty acids, minerals, and amino acids. Both fatty acids and amino acids are organic compounds, but have some more additional requirements above being merely an organic compounds and minerals are basically “everything else”.

There’s no strict definition but it effectively means anything you need to ingest* for proper health / biochemical functioning that isn’t used for its calories. Vitamins are organic (carbon containing) small molecules that fit this definition, and minerals are elemental (zinc, iron, selenium, etc.).

All vitamins are good for you in correct doses and in fact necessary for proper health. Excess doses, especially of the fat soluble vitamins (A D E K) can be toxic, though.

*Vitamin D is the exception that you can synthesize it with sunlight.

The first part of your question has been answered, so let me jump to the 2nd.

Most inexpensive vitamins are coal tar derivatives. A performance test performed by a NY state or local college (sorry, I learned about this in the 90s and don’t recall most of the details) on their athletic teams showed that players consuming the cheap OTC vitamins performance degraded, but recovered when they stopped using them.

Short version, it is a molecule your body needs, but cannot make itself.

The exception to the rule is D vitamin, which is synthesized in your liver in an unfinished state. It is then transported to your skin, where sunlight drives the reaction that turns it into functional D vitamin.

Further chatting along; you need all vitamins in proper doses, to function optimally. Dark winters in the North for example, leads to D-vitamin deficit, which then again plays a part in so called Vinter Depression. We are all affected by the dark, but people with darker skin are hit harder, because their dark skin produces less D-Vitamin. They are adapted to sunshine, while we light skinned northerners, get serious sunburns if we are too much in the sun. But we lost our skin color, to make the most of the light there is, up north.

Lack of C Vitamin led to scurvy, for sailors and pirates alike. It was cured/prevented with lemons. Too much C Vitamin does not harm, the excess goes straight through your body.

While too much A-Vitamin can cause serious damage to you eyesight.