Fish

Known for their omega 3 fats and for being a high protein food, fish are also a good source of vitamin B12. Mackerel provides the most vitamin B-12 with 19μg per 100g serving (317% RDA), followed by Herring (312% RDA), Salmon (302% RDA), Tuna (181% RDA), Cod (167% RDA), Sardines (149% RDA), Trout (130% RDA), and Bluefish (104% RDA).