Of course vitamins don't stop you being or becoming an alcoholic. Rather alcoholism and vitamins go together in a negative way. You don't get enough vitamins when you're an alcoholic and that is why Jane, my partner, has a stack of vitamins that she is taking on a daily basis; before the next 7 day binge :-)
When she is not drinking she'll eat OK but too little (in my opinion). When I wasn't living with her she would tend to lose weight and become very thin (below 8 stones for a 5 foot 6 inch tall women). When she goes on a binge she eats very badly indeed, normally eating biscuits, nuts and drinking lots of high carbohydrate drinks as the neat Vodka makes her thirsty as hell (dehydrating her badly).
Her main source of food when she is on a binge drink is the calories in the alcohol (empty calories). On some occasions in the past, less so now, she would become skeletal after a binge and it would take months to get the weight back as she eats so little.
She takes multivitamins, Antabuse, Milk Thistle, Silybum marianum (Evidence exists that milk thistle may be hepatoprotective), omega type oils (for joints) and various other drugs such as Amytripyline and Prozac.
The Amytripyline helps with anxiety and helps her to sleep. The Prozac of course is meant to help with depression, but she says it doesn't help but still takes it as a kind of crutch it seems to me.
So, it pays to take vitamins as a supplement to your diet as an alcoholic as your normal diet will not be good particularly if you are drinking daily as opposed to Jane who binge drinks.
Alcohol is a poison to the body and damages it. Add to that the lack of nutrition that an alcoholic will suffer from and the combination is noticeable in ill health.
Jane is in hospital about half a dozen times per year or more for ill health directly related to alcoholism. This could be for example pancreatitis, stomach complaints or other unspecified illnesses.
Research indicates that alcohol interferes with the use of vitamin C and E and Selenium in the body. These antioxidants protect the body's healthy molecules against damage from unstable molecules.
I think alcohol gradually breaks down the body until it kills you. Look at George Best. He finally got ill one more time and the body couldn't be repaired. Bona Fide alcoholics loook frail and broken down. Maybe the unstable molecules have damaged the healthy cells to such an extent that there is no repairing them.
Photo of Milk Thistle courtesy Wikipedia (creative commons)
Source: MotherNature.com and mainly my personal experience.