Hello! I nursed my son for 2yrs. I'm not a Dr. and don't pretend to play one on the web but, I believe if you keep your water up ( one of the most important things in nursing, as I am sure you know), take your vitamins, and get in your calcium with either plain yogurt and/or cheese, you will be fine. Just make sure you are eating enough. Check to see what the calorie intake should be for a nursing mother (if you don't already know) and keep it there. Keep eating healthy carbs. Just stay away from the white flour, sugars, rice, and potatoes. They really have no nutritional value that you can't get from other foods. (Except for the sugar, bad sugar!!!)
Hope this helps!