2. no problem.

3, but don't take it before going to bed, because when sleeping, the drug may stay in the stomach for a long time, causing the drug to stimulate the stomach wall for a long time and damage the stomach.

Vitamins are usually taken half an hour after meals, however, the specific instructions shall prevail.

Fresh fruits and vegetables, eggs, meat, etc. It is the best source of vitamin C and other vitamins. Suggest supplementing food. When the intake is insufficient, you can consider taking medicine supplement under the guidance of a doctor.