Why did organic life start using vitamins, where did vitamins come from

Vitamins are co-enzymes, but why did organic matter start using vitamins in the first place? Are the enzymes designed to need vitamins are is it just coincidence that the enzymes were helped by vitamins? Where did the vitamins come from originally since we get most of our vitamins from foods, and the foods have vitamins for the same reason we do you’d assume at one point life just started independently using vitamins until it caught on for all the life forms.

I hope this small tidbit helps…

Sitting in a biology class last week we discussed some experiments folks have done to simulate conditions on ancient earth (pre-life). These experiments produced many “organic chemicals” including amino acids, nucleotides, phospho-lipids and (some) vitamins.

So that might answer where they came from, at least originally.

There are many many coenzymes besides the ones we refer to as vitamins. Vitamins are just that class of coenzymes (or their precursors) that any particular organism is unable to synthesize from scratch, and must acquire from other organisms that *are * able to synthesize them.

Mammals, including humans, have lost the ability to synthesize these particular coenzymes, because evolutionary it was more efficient to rely on getting them from food (because they are mostly pretty ubiquitous in living matter) than to maintain the metabolic machinery for making them. This ability is retained by many bacteria and plants, so that these organisms generally don’t need to acquire vitamins from the environment. Mammals do, however, have the ability to synthesize a wide variety of other coenzymes.

Questions on why our metabolism has evolved the way it has are quite deep, I think. Although the answer to why enzymes use cofactors/vitamins will always be because it represents some sort of evolutionary pinnacle of efficiency and versatility, taking things a step further and asking why this particular biochemistry mechanism has won the evolutionary race is more challenging.

I don’t know the answer, although I have no doubt that many theories have been advanced. I remember reading about a similar question of molecular evolution asking why proteins are so big, the proposed answers made sense but they were highly interpretive, not cut and dried by any means.

In his book At Home in the Universe, Stuart Kauffman describes some computer modeling he did looking at the levels of interconnectedness between points in a pattern, and he found that the level that gave the most “life-like” behavior (ie, not settled down into a stagnant, unchanging behavior and also not just random-looking chaos) was just over two. That corresponds, in biology, to enzymes that usually can act alone, but occasionally require a coenzyme.

It’s hard to explain, but very interesting - read the book if you’re curious.