B12 or B Complex

I haven't been feeling my best of lately, and I wonder what is more beneficial to me - just B12 or a B Complex?? I remember that KP once said you get X amount of a percentage of vitamins, so if you get one that is at least 200% (I believe) you are ok - you just the rest. Any advice is most welcomed!!

I would take both so you are covered

I have trouble with B complex... b-6 gives me hot flashes and palpitations,(I haven't had wls yet so maybe it's different) all the same be careful add slowly... Lexia