Iv never heard that b 4..:/..talk 2 ur dr about it..but they.put vitamin c in prenatal vitamins..so I doubt it wud.cause a problem...
Listen to your doctor. If you have questions, that's who you should go to.
What your body doesn't use you urinate out. Ask your doctor if there is anything you should worry about.
Get the flu jab if you can. I always get it and it is safe for pregnancy.