Vitamins are chemicals that humans benefit from getting a sufficient quantity of in our diets. The primary sources for those vitamins is plants (fruits and vegetables). A very few, as I recall, are obtained from meats.

So, vitamins are produced by plants, and we take advantage of that with our diet.

Farmers grow plants to make a living. They are ready, willing and able to spend money to increase their crop production, and they use a variety of fertilizers for that purpose. But, they don't use vitamins.

It is hard to imagine aquatic plants being so different from terrrestrial plants that they alone benefit greatly from adding vitamins to their environment, the water. So, it is going to take a lot of very persuasive evidence before I will believe that there are vitamins that I can add to my aquarium that will benefit my plants.