Taking vitamins and supplements in benzo withdrawal and recovery can have undesirable consequences, these are discussed in Supplements and Withdrawal.
Even when well it may pay to do your homework and make informed decisions when deciding to add things like vitamins and supplements to your body. These articles look like they come from good sources. They include discussions on who needs to take vitamins, what needs to be taken, how much needs to be taken, dangers involved and pitfalls to avoid.