Although vitamins and minerals are required in minute amounts compared with protein, lipid, and so forth, they are critically important, … Every micronutrient has a deficiency disease associated with it, the effects of which are sometimes irreversible or fatal. For a few vitamins and most minerals, excess can be equally detrimental, resulting in toxicity.
I agree for the pond owner it is a good hedge to feed a food with vitamins but have to as how do fish in ponds not getting vitamins in food survive?
