vitamins ...and help

so I've been counting my calories using my fitness pal the past 10 days actually counting everything. I don't usually eat over 1200 calories a day (the goal is 1400) but I'm also breastfeeding and completely forgot that I should be eating enough calories especially since I don't usually take vitamins. I don't workout because I'm always with kids but I do squats crunches side leg lifts and jumping jacks. can someone give me tips on how to lose weight what am I doing right what am I doing wrong. does anyone have vitamin recommendation besides prenatals