Milk and dairy products Milk and dairy products like yogurt and cheese are great sources of protein and several vitamins and minerals, including vitamin B12. One cup (240 ml) of whole milk supplies 46% of the DV for vitamin B12 . Cheese is also a rich source of vitamin B12. One large slice (22 grams) of Swiss cheese can contain about 28% of the DV . Full fat plain yogurt can also be a decent source. It has even been shown to help improve vitamin B12 status in people who are deficient in the vitamin.