I'm not going to say that a vegan can't go low carb because it is possible. But, it isn't easy and you will need to really, really work on nutrition. The reason you are finding you have to eat such low calories is that being a vegan many of the foods you can eat are high carb.
The book New Atkins for a New You by Eric Westman does have information about how vegetarians and vegans can follow Atkins so you might want to look at it.
You may want to put some nuts into your diet as well since that will give you some healthy fats.
Last edited by Koshka; 04-22-2012 at 12:08 PM.