you'll just pee out whatever you don't use, I would find a 1000mg form with methyl b9. I personally like this one by jarrows: https://www.amazon.com/Jarrow-Formulas-Pyridoxal-5-phosphate-Lozenges-Supports/dp/B01IJR5VM2/ref=sr_1_4_a_it?ie=UTF8&qid=1529793182&sr=8-4&keywords=jarrows+b12