It would be easy to eat that amount of berries to get one day's worth of vitamin C, but you don't need to eat that much as long as you're getting other sources. Here's some nice way to get strawberries into your diet:
United States Department of Agriculture National Nutrient Database for Standard Reference. "Strawberries, raw." Accessed October 22, 2010. http://www.nal.usda.gov/fnic/foodcomp/search//.