hello doc..i just want to know wich vitamins...

Vitamins that help with increase weight ?
1. vitamin C 
2. vitamin B1 / B6
3. vitamin A
how to take those vitamins ?
- via food and diet 
- via multi vitmains pills such as centrum 
general advices :
1. consult a nutritionist to guide into a better and suitable diet
2. drink more fluids 
3. make sure that your diet contain plenty of health calories
4. pay attention to dinner meal and dont miss it
5. make sure that you are not taking any medication causes weight loss as a side effect
6. exercise
7. avoid stress and anxiaty 
Causes of weight loss :
1. unhealthy diet 
2. smoking
3. stress
4. medication side effects 
5. chornic diesease