I personally found through trial and error supplementing with active forms, so called tissue-ready forms of B vitamins, etc. like the Mayo Clinic online store sells were the most symptom relieving. They are designed for those who cannot convert non-active B vitamins to their active forms (the store's description says). I have developed some absorption problems and have found that these help.
By far the most knowledgeable laypersons I have read on topics such as vitamin B online are a Pernicious Anemia group. They really impress upon the need to have baseline labs drawn for one's doctor to evaluate prior to starting supplementation (I mention this for the benefit of others reading this).