I have that book and the author makes a good case for nutrition and supplementation to assist in sobriety efforts, especially for those who have drank excessively for years, and done a lot of physical damage. I myself took a B vitamin complex for my nervous system, and milk thistle for my liver, during the first 90 days.
However, it is pretty well established that vitamins and herbal supplements are no substitute for proper diet, as they aren't as readily absorbed. And recent independent testing of herbal supplements showed a huge range of actual purity.. some had almost none of the specified ingredient.. it is an unregulated industry, which give one pause. Especially when taking a lot of them.
I think the most important thing is to eat well - lots of veggies, high quality protein, and water. And get some exercise every day, which helps to improve sleep and stabilize our mood.