Unlike Hannibal Lecter, the thought of eating an animal liver might not make you crave some fava beans and a nice Chianti. However, the health benefits might help to sway your mind. Not only are animal livers heavy in vitamins, they also contain high amounts of protein. Many countries have adopted chicken, cow, cod, and many other organ meats — also known as offal — into their cuisines.

Depending on what animal from which a liver is derived, the amount of vitamins and nutrients can vary. Organ meats can also be high in cholesterol. "However, liver is rich in iron and vitamins. A small serving (3 ounces) is ok about once a month," according to the American Heart Association. Below is a list of nutrient-rich livers for a healthy diet.

Veal Liver

The liver of a baby calf is not unlike the meat of the animal. Many people find that veal tastes better than steak. What's more, because of the calf's young age, the animal is more likely to be healthier and free of toxins. Calf's liver is packed with vitamin A, which is important for eye, skin, teeth, skeletal, and soft tissue health. It also helps to boost the body's immune system. Vitamins B6 and B12 are available in calf's liver, which help to form healthy red blood cells.

Duck Liver

Duck liver, also known as foie gras, is a common food item in France and can sometimes be very expensive. Nevertheless, it's rich in proteins, minerals, and vitamins including copper, vitamin A, and nine essential amino acids, to name a few. Copper is an essential trace mineral, which means only a small amount is needed for the human body. Trace minerals are also known as micro-minerals and are important for building bones, making hormones, and regulating your heartbeat. The American Cancer Society has cited that copper has antioxidant properties and can help to combat cancer.

Cod Liver

The benefits from this liver is in the oil. Cod liver oil has been used to treat many ailments. Like many other fish oils, it is packed with nutrients like beta-carotene, vitamin A, vitamin D, and omega-3 acids, and contains less saturated fats than other oils. Vitamin D is important for calcium absorption. Deficiencies of this vitamin were popular in the 20th century. Poor and malnourished children in northern cities all over the United States faced vitamin D deficiencies. Cod liver oil was important in helping to combat the lack of this vitamin and helped to prevent diseases, such as rickets. The liver oil has also been used on skin for wounds, and since it does contain fatty acids when ingested regularly, cod liver also helps to prevent blood from clotting.

Chicken Liver

The trick with eating this type of liver is to make sure that the chicken is organic. If not, you run the risk of eating a liver that is filled with toxins and hormones. Organic chicken liver contains Vitamin B12; a deficiency in this vitamin can cause anemia. Vitamin B12 can prevent memory loss, boost mood and energy, slow aging, and strengthen the immune system. Chicken liver, since it's lower in vitamin A, can also be consumed more frequently as opposed to beef or duck livers.

Regardless of their many health benefits, organ meats have been previously unpopular in the United States. Now, however, offal meats are starting to make their way onto fine dining menus across America. So, the next time you decide to dine out and a liver dish is on the menu, go ahead and try it — the taste might actually surprise you (in a good way).