I see you have made a few post about wine kits. Just remember that a wine kit will have the yeast nutrient already added in so you should not need to add more. Mosti Mondial is the only Kit I know that actually has you add the (supplied) nutrient into the must close to the end of primary fermentation. If you are making country wines etc. from a recipe then you will obviously need to keep some on hand.
I agree with Mike on this, especially if you are using the yeast, which came with the kit. Everything is pre-adjusted, except for the Mosti kits, which have taken this into account and have supplied additional nutrients.
The possible exception might be if you use a yeast, which did not come with the kit. If the kit supplied yeast happens to have a low need for nutrients, while the yeast you have decided to use has a
much higher need for nutrients, like BM45, you might consider using some additional nutrient. In such a case use only about half of what the nutrient instructions say to use. Half, because the kit will always already have some nutrient included.
Until one gets some experience, one really does need to be careful about this sort of situation. Stick with the kit supplied yeast for several kits, then maybe start carefully experimenting.
A case in point - After making wine for about 2 years, I decided to use a different yeast. That yeast had a very high nutrient requirement, but I didn't add any extra nutrient to the kit. I hadn't bothered to research the yeast strain. That yeast also had a tendency of producing loads of H2S (rotten egg smell) when stressed. I ended up with a huge H2S issue on my hands. I finally got rid of the H2S, but the wine was never what it otherwise would have been.