If we're talking about beer, then I would say that would be serious overkill. If we're talking wine, then maybe that much would be okay. If we're talking mead, then that much or potentially more would be needed. If you're boiling your fermentables at any point then adding the nutrient at the end of the boil is optimal.
An all malt beer should have nearly enough nutrients if the gravity is reasonable 1.030+ regardless if it's all grain or extract. Down around that gravity or lower you might include a nutrient addition. If you're using a large percentage of adjuncts or simple sugar then you may also want to use some nutrient.
What are you making? What's your recipe?