The liver of mammals, fowl

Fowl

Fowl is a word for birds in general but usually refers to birds belonging to one of two biological orders, namely the gamefowl or landfowl and the waterfowl...

, and fish are commonly eaten as food

Food

Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...

 by humans. Domestic pig

Domestic pig

The domestic pig is a domesticated animal that traces its ancestry to the wild boar, and is considered a subspecies of the wild boar or a distinct species in its own right. It is likely the wild boar was domesticated as early as 13,000 BC in the Tigris River basin...

, ox

Beef

Beef is the culinary name for meat from bovines, especially domestic cattle. Beef can be harvested from cows, bulls, heifers or steers. It is one of the principal meats used in the cuisine of the Middle East , Australia, Argentina, Brazil, Europe and the United States, and is also important in...

, lamb, calf

Calf

Calves are the young of domestic cattle. Calves are reared to become adult cattle, or are slaughtered for their meat, called veal.-Terminology:...

, chicken

Chicken

The chicken is a domesticated fowl, a subspecies of the Red Junglefowl. As one of the most common and widespread domestic animals, and with a population of more than 24 billion in 2003, there are more chickens in the world than any other species of bird...

, and goose

Goose

The word goose is the English name for a group of waterfowl, belonging to the family Anatidae. This family also includes swans, most of which are larger than true geese, and ducks, which are smaller....

 liver

Liver

The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...

s are widely available from butchers and supermarkets.

Liver can be baked, boiled, broiled, fried, stir-fried

Stir frying

Stir frying is an umbrella term used to describe two Chinese cooking techniques for preparing food in a wok: chǎo and bào . The term stir-fry was introduced into the English language by Buwei Yang Chao, in her book How to Cook and Eat in Chinese, to describe the chǎo technique...

, or eaten raw (lebanese cuisine, liver sashimi

Sashimi

Sashimi is a Japanese delicacy. It consists of very fresh raw meat, most commonly fish, sliced into thin pieces.-Origin:The word sashimi means "pierced body", i.e...

). In many preparations, pieces of liver are combined with pieces of meat or kidneys, like in mixed grill

Mixed grill

Many regional cuisines feature a mixed grill, a meal consisting of a traditional assortment of grilled meats. Versions of the mixed grill include:...

 or meurav Yerushalmi. Liver is often made into spreads

Spread (food)

A spread is a food that is spread with a knife onto bread, crackers, or other bread products. Spreads are added to bread products to provide flavor and texture, and are an integral part of the dish, i.e. they should be distinguished from condiments, which are optional additions...

. Well-known examples include liver pâté, foie gras

Foie gras

Foie gras ; French for "fat liver") is a food product made of the liver of a duck or goose that has been specially fattened. This fattening is typically achieved through gavage corn, according to French law, though outside of France it is occasionally produced using natural feeding...

, chopped liver

Chopped liver

Chopped liver is a spread popular in Jewish cuisine.It is often made by sautéeing or broiling liver and onions in schmaltz; adding hard-boiled eggs, salt and pepper, and grinding that mixture...

, and leverpostej

Leverpostej

Leverpostej , leverpostei , leverpastej , , maksapasteija or leverpastei is a "pâté" made of pork liver and lard, which is a popular spread in northern Europe...

. Liver sausage

Sausage

A sausage is a food usually made from ground meat , mixed with salt, herbs, and other spices, although vegetarian sausages are available. The word sausage is derived from Old French saussiche, from the Latin word salsus, meaning salted.Typically, a sausage is formed in a casing traditionally made...

s such as Braunschweiger

Braunschweiger

Braunschweiger is a type of liverwurst which, if stuffed in natural casings, is nearly always smoked...

 and liverwurst

Liverwurst

The German , that translates literally as "liver sausage," is the typical sausage served in Germany, Austria, Hungary, Serbia, Slovenia, the Netherlands, Finland, Sweden and Romania . Liverwurst normally contains pigs' livers, rather than calves' livers and also contains veal...

 are also a valued meal. Liver sausages may also be used as spreads.

Animal livers are rich in iron and vitamin A

Retinol

Retinol is one of the animal forms of vitamin A. It is a diterpenoid and an alcohol. It is convertible to other forms of vitamin A, and the retinyl ester derivative of the alcohol serves as the storage form of the vitamin in animals....

, and cod liver oil

Cod liver oil

Cod liver oil is a nutritional supplement derived from liver of cod fish. It has high levels of the omega-3 fatty acids, EPA and DHA, and very high levels of vitamin A and vitamin D. It is widely taken to ease the symptoms of arthritis and for other health benefits...

 is commonly used as a dietary supplement

Dietary supplement

A dietary supplement, also known as food supplement or nutritional supplement, is a preparation intended to supplement the diet and provide nutrients, such as vitamins, minerals, fiber, fatty acids, or amino acids, that may be missing or may not be consumed in sufficient quantities in a person's diet...

. Traditionally, some fish livers were valued as food, especially the stingray

Common stingray

The common stingray is a species of stingray in the family Dasyatidae, found in the northeastern Atlantic Ocean and the Mediterranean and Black Seas. It typically inhabits sandy or muddy habitats in coastal waters shallower than , often burying itself in sediment...

 liver. It was used to prepare delicacies, such as poached skate liver on toast in England, as well as the beignets de foie de raie and foie de raie en croute in French cuisine

French cuisine

French cuisine is a style of food preparation originating from France that has developed from centuries of social change. In the Middle Ages, Guillaume Tirel , a court chef, authored Le Viandier, one of the earliest recipe collections of Medieval France...

.

Poisoning

Very high doses of vitamin A

Vitamin A

Vitamin A is a vitamin that is needed by the retina of the eye in the form of a specific metabolite, the light-absorbing molecule retinal, that is necessary for both low-light and color vision...

 have the potential to be toxic and can cause hypervitaminosis A

Hypervitaminosis A

Hypervitaminosis A refers to the effects of excessive vitamin A intake.-Presentation:Effects include* Birth defects* Liver problems* Reduced bone mineral density that may result in osteoporosis* Coarse bone growths...

, a dangerous disorder. Russian sailor Alexander Konrad

Alexander Konrad

Alexander Eduardovich Konrad was a Russian sailor. Along with Valerian Albanov, he was one of the only two survivors, and the only surviving sailor of the ill-fated Brusilov expedition.-Biography:...

, who accompanied explorer Valerian Albanov

Valerian Albanov

Valerian Ivanovich Albanov was a Russian navigator, best known for being one of only two survivors of the ill-fated Brusilov expedition of 1912.-Biography:...

 in a tragic ordeal over the Arctic

Arctic

The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...

 ice in 1912, wrote about the awful effects of consuming polar bear

Polar Bear

The polar bear is a bear native largely within the Arctic Circle encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is the world's largest land carnivore and also the largest bear, together with the omnivorous Kodiak Bear, which is approximately the same size...

 liver. Also, in 1913, Antarctic explorers Douglas Mawson

Douglas Mawson

Sir Douglas Mawson, OBE, FRS, FAA was an Australian geologist, Antarctic explorer and Academic. Along with Roald Amundsen, Robert Falcon Scott, and Ernest Shackleton, Mawson was a key expedition leader during the Heroic Age of Antarctic Exploration.-Early work:He was appointed geologist to an...

 and Xavier Mertz

Xavier Mertz

Xavier Mertz was a Swiss explorer, mountaineer and skier, from Basel. He took part in the Far Eastern Party, a 1912–13 component of the Australasian Antarctic Expedition, which claimed his life...

 were both poisoned, the latter fatally, from eating husky

Sled dog

Sled dogs, known also as sleigh man dogs, sledge dogs, or sleddogs, are highly trained types of dogs that are used to pull a dog sled, a wheel-less vehicle on runners also called a sled or sleigh, over snow or ice, by means of harnesses and lines.Sled dogs have become a popular winter recreation...

 liver.

Poisoning is less likely from consuming oil-based vitamin A products and liver than from consuming water-based and solid preparations.

Inuit

Inuit

The Inuit are a group of culturally similar indigenous peoples inhabiting the Arctic regions of Canada , Denmark , Russia and the United States . Inuit means “the people” in the Inuktitut language...

 will not eat the liver of polar bear

Polar Bear

The polar bear is a bear native largely within the Arctic Circle encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is the world's largest land carnivore and also the largest bear, together with the omnivorous Kodiak Bear, which is approximately the same size...

s (a polar bear's liver contains so much vitamin A as to be poisonous to humans), or seal

Pinniped

Pinnipeds or fin-footed mammals are a widely distributed and diverse group of semiaquatic marine mammals comprising the families Odobenidae , Otariidae , and Phocidae .-Overview: Pinnipeds are typically sleek-bodied and barrel-shaped...

s.

Unrelated to its vitamin content, pufferfish

Pufferfish

Tetraodontidae is a family of primarily marine and estuarine fish of the Tetraodontiformes order. The family includes many familiar species which are variously called pufferfish, balloonfish, blowfish, bubblefish, globefish, swellfish, toadfish, toadies, honey toads, sugar toads, and sea squab...

 (which is consumed in Japanese cuisine

Japanese cuisine

Japanese cuisine has developed over the centuries as a result of many political and social changes throughout Japan. The cuisine eventually changed with the advent of the Medieval age which ushered in a shedding of elitism with the age of shogun rule...

 as fugu

Fugu

is the Japanese word for pufferfish and the dish prepared from it, normally species of genus Takifugu, Lagocephalus, or Sphoeroides, or porcupinefish of the genus Diodon. Fugu can be lethally poisonous due to its tetrodotoxin; therefore, it must be carefully prepared to remove toxic parts and to...

) liver contains the highest concentration of the neurotoxin which characterizes the species. As a result, it is generally not eaten, and its consumption is tightly regulated by Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

ese law.