First think about what B-12 is???????? To the scientist B-12 is one of the more deadly chemicals, only a very small amount of what they make B-12 out of will kill you. Look in the Dr. Clark books on how to make B-12.
The fruits and berries have all you need and all the things we have read about as far as vitamins are concerned was all a fraud created by a medical scientist that received a Nobel and made the medical industry billions and sent millions to an eary grave.
If you read my first schooling book, the MD explains that all medical/scientific methods are FAKE/FALSE and to not waste one dime of your money on them. Test are made to make them money, they may be false or may be true, but they do nothing to make you well again, so they are a waste.
I ignore all vitamin information, I have been there and done that and will never take another one the rest of my life.