You should be taking the B12 on an empty stomach, 1-2 hours before eating or drinking (water is OK) -- early morning is good. Then you can take the R-Lipoic Acid (RLA) with the rest of your supplements. 100 mg of
stabilized RLA per day should be fine. If it doesn't help with the first bottle, it likely won't.
You can find other supplements for PN discussed in the
PN Tips, Resources, Supplements & Other Treatments Sub-Forum.
Doc