Multivitamins and a good, steady diet of 3 meals a day, etc. Regardless of which drug, narcotics addiction is tough on the body because active addicts don't eat properly, if at all. Returning to being human is equally hard for the body as it is the mind. As is true with 99% of things in life, consistency is key. Sleep until you wake and feel rested (usually 6-9 hours a night). Don't oversleep either, can actually work against you and isn't a healthy routine for getting life stuff done during the remaining hours in the day (work, meetings, family time, etc).
Beware of focusing too much on food, I've known many who substituted sweets for drugs and ended up having to address how a newfound food addiction was impacting their life. Balance, another key to living spiritually.