I'd probably just suggest that she switches her breakfast for eggs. Obviously I don't know if your G/F is a Vegan, whether she's allergic or simple doesn't like eggs. I'm a real picky eater so I tend to have a deficiency in nearly all the vitamins. Hypokalemia is one of many (I don't like bananas). There's nothing wrong with taking vitamins but you shouldn't really be substituting them for food. Given my medical condition I'm forced to take B1, B12, K, Mg... the list is endless. Good luck to your G/F, I'm sure she'll find something she likes eating that will get her B12 levels up. It may also be worth going over her diet and how it has changed since she was testing a year ago - if it hasn't then it could be due to a medical reason or simply just a change of lifestyle.