drinks!!

Briana
Need some advise.. I normally drink a half of a diet soda every other day due to the lack of b12 in my system. Now that we are newly excepting i was trying to see if I switched to sprite of that would be better the diet caffeine free Diet Coke.. I know water and 100% juice is better but sometimes my body needs that extra sugar and I have tried everything. Please let know what you think? Also is it safe to add lemon and fruit into water? I heard to make sure to clean fruit first but wanted to make sure it was safe to allow it to sit in water through out day or few hours