Vitamin B1 (thiamine) is usually recommended as a supplement during alcohol withdrawal. As mentioned above, alcohol depletes our levels, that's why it's an effective hangover "snake oil" cure, most expensive hangover cures are vitamin B and aspirin (the last sentence was purely educational folks, no reason to have a few drinks).
I usually buy vegemite and have it on toast for breakfast. An Australian friend introduced me to it, it took a while to get used to the taste, but once you adjust, it's a great energy boost.