Along with water quality, growth in finfish is typically based on quality and quantity of feeding protein (amino acids) and fatty acids - not vitamins.
Some species of fish actually grow faster/larger depending on how often they are fed each day - some species showing more optimum growth with 2 feedings a day, compared to 3 or 4. Lots of factors regarding growth in a fish, but overall most commercial foods will supply an ample amount of vitamins and trace minerals for normal growth.