Chronic drinkers are very likely to have a vitamin B deficiency. Oral strong tablets containing vitamin B compounds contain these B vitamins in amounts that exceed normal dietary requirements. They are relatively cheap and no serious adverse effects have been reported from them.
Higher-dose oral vitamin B supplements appear to be better absorbed than lower-dose oral supplements, and they correct vitamin B deficiencies without causing adverse effects. No major interactions with other medications are known. There is not enough thiamine in strong tablets containing vitamin B compounds to correct thiamine deficiency in chronic drinkers, so additional thiamine supplements are needed to prevent Wernike-Korsakov syndrome.
The authors recommend the administration of vitamin B preparations and state clear conditions for this.
Should GPs prescribe vitamin B compound strong tablets to alcoholics? | Link to source