i've had b12 issues as well. i've experienced cognitive problems, weird physical sensations, and depression. i think tempeh is a cultured or fermented product that provides b12. i started making my own tempeh because it's so expensive but the ingredients are super cheap. basically you cook the beans, ad the culture and keep it nice & warm for a couple of days. it makes me thing of blue cheese the way the mycelium (
) grow. traditionally made with soybeans (which loose their issues when fermented) but many cheaper beans can be used. let me know if you're interested and i'll post linkes to info.