Who needs to do a study to test a vitamin when it was originally discovered to be an essential thing for life, ie. living processes, to work.?

How insane can one get? Of course the group getting a low level or a deficiency will suffer - because vitamin A enhances the maturation of cells into mature tissues it has been found that excess amounts may induce in pregnant women a maturation of tissue before the embryonic processes have arrived at the stage of needing to be mature thus there have been teratisms associated with vitamin A throughout history. Therefore there is always a warning with vitamin A that no more than 10,000 IU of vitamin A should be given to a pregnant mother, likely a very low level to cover their asses, while I suggest to people that they need at least 50,000 IU daily. But at least this warning in pregnant women is written in the medical bibles so every MD should already know.

Do we need to do controlled trials to test every vitamin to see if they work where they are given and see the control groups suffer without them? Maybe for toxic drugs you need to do controlled studies but to test a vitamin is like studying water or oxygen - the control group without it will die.The abstract does not say how much vitamin A was given. But they talk of a deficiency?