Animal liver and kidneys Organ meats are some of the most nutritious foods out there. Liver and kidneys, especially from lamb, are rich in vitamin B12. A 3.5-ounce (100-gram) serving of lamb liver provides an incredible 3,571% of the Daily Value (DV) for vitamin B12 . While lamb liver is generally higher in vitamin B12 than beef or veal liver, the latter two may still contain about 3,000% of the DV per 3.5 ounces (100 grams) . Lamb liver is also very high in copper, selenium, and vitamins A and B2 . Lamb, veal, and beef kidneys are also high in vitamin B12. Lamb kidneys provide about 3,000% of the DV per 3.5-ounce (100-gram) serving. They also provide more than 100% of the DV for vitamin B2 and selenium .