so I'm wanting to try the Vitamin A tablets to clear up the last bit of red marks I have. and finally have clear skin but I have a few questions about it. like how much should I start with? how long should I take it before increasing or decreasing the iu's I take in? also what should I be washing my face with and moisturizing with while taking this? and my skin is very dry so would it be okay to take the soft gel tablets? I've read many review and lots of information about it and they're all good so I'm hoping it'll have the same affect on me please help me out a little bit with these questions 
Vitamin A helps to keep sebum under control, vitamin B5 helps too but that would need super overdose to see effect.
An vitamin A overdose can be harmful to bones and skin, causing weakness and brittleness, even leading to fatigue and vomiting. Excessive intake of vitamin A is toxic, at dosages of around 20-25,000 IU daily.Consuming more than 25,000 IU of vitamin A per day (adults) and 10,000 IU per day (children) from either food or supplements or both is known to betoxic.
If your acne seems under control you can reduce the intake gradually.
Not to over wash your wash either with just plain water or gentle mild cleaner since you have dry skin. Moisturise as you can but exfoliate once in a while salicylate acid
softgel and tablet are both different form so only get the tablet form will do fine.