Raw liver is one of the most nutrient-dense foods on the planet, but eating it uncooked carries real risks of bacterial, viral, and parasitic infection. The nutritional profile is impressive by any measure: 100 grams of raw beef liver contains roughly 23,220 RAE of vitamin A (over 25 times the daily requirement), 200 micrograms of vitamin B12 (about 8,300% of what you need daily), 529 micrograms of folate, and 7.4 milligrams of iron. Whether that nutrition is worth the safety trade-off depends on how much risk you’re willing to accept.
What Makes Liver So Nutrient-Dense
Liver functions as a storage organ in animals, concentrating vitamins and minerals at levels that dwarf virtually every other food. The vitamin A content alone puts it in a category of its own. A single 100-gram serving of beef liver provides enough vitamin A for weeks, which is actually a concern in itself (more on that below). The B12 content is similarly extreme, delivering enough in a small portion to cover your needs for days.
The iron in liver is primarily heme iron, the form your body absorbs most efficiently. Human absorption studies show that heme iron is absorbed at roughly 13.5%, compared to about 6–7% for nonheme iron from plant sources. This makes liver particularly effective for people dealing with iron deficiency. The folate content is also notable, rivaling supplements, which is unusual for an animal food.
Does Raw Liver Offer More Nutrition Than Cooked?
This is the main argument raw liver advocates make, and there’s some truth to it. Cooking does reduce certain nutrients. Research on heat treatment of meat found that cooking reduced heme iron content by 62% and decreased soluble iron by 50%. Cooking also significantly lowered cysteine, an amino acid that aids iron absorption. So on paper, raw liver delivers more bioavailable iron than cooked liver.
That said, the difference is less dramatic than it sounds. Cooked liver is still extraordinarily rich in iron, B12, and vitamin A. The starting concentrations are so high that even after cooking losses, liver remains one of the most nutrient-dense foods you can eat. The practical gap between raw and lightly cooked liver, in terms of what your body actually gets, is smaller than the raw numbers suggest. And the factor in meat that enhances absorption of nonheme iron from other foods in your meal isn’t affected by heat at all.
Bacterial and Viral Contamination
Raw liver can harbor several dangerous pathogens. The most well-documented risk involves hepatitis E virus, particularly in pork liver. A Canadian study testing grocery store pork livers found that 4% of raw samples were positive for hepatitis E RNA. In France, where raw and undercooked pork liver dishes are traditional, roughly 4% of pork livers entering the food chain were contaminated, and the virus was detected in 3% to 30% of food products containing raw pork liver. French health authorities estimated that foods containing pork liver may be responsible for nearly 40% of domestically acquired hepatitis E cases.
Hepatitis E causes liver inflammation that can range from mild to severe. In most healthy adults it resolves on its own, but it can be dangerous for pregnant women and people with compromised immune systems. The virus is inactivated by thorough cooking at 71°C (160°F) for 20 minutes.
Beyond hepatitis E, raw liver can carry Salmonella and Campylobacter, two of the most common causes of food poisoning. These bacteria are killed by proper cooking but thrive in raw organ meat. Beef liver carries a lower viral risk than pork liver for hepatitis E specifically, but bacterial contamination is a concern across all species.
Parasitic Infections
Eating raw or undercooked organ meat also exposes you to parasites. Toxocariasis, caused by roundworm larvae, is one documented risk. While rare, infections can cause fever, coughing, abdominal pain, and enlarged liver. In some cases, larvae migrate to the eyes and cause vision problems, seeing spots or flashes of light, eye irritation, or even vision loss. The CDC notes that people can get infected by eating undercooked or raw meat.
Vitamin A and Copper Overload
The very thing that makes liver nutritionally remarkable also makes it risky in large or frequent servings. At over 23,000 RAE of vitamin A per 100 grams, beef liver can push you past safe intake levels quickly. Chronic vitamin A toxicity causes headaches, nausea, joint pain, and in severe cases, liver damage. A single large serving won’t cause problems, but eating liver daily, raw or cooked, can accumulate to harmful levels over weeks.
Copper is the other nutrient to watch. Beef liver is extremely high in copper, and the body’s tolerance for excess copper is limited. The dietary requirement is only 0.9 milligrams per day, and toxicity becomes a concern at prolonged intake roughly 40 times that level. Regular liver consumption, especially in large portions, can push copper intake high enough to cause nausea, abdominal pain, and eventually liver damage. Most nutrition experts recommend limiting liver to one or two servings per week for this reason.
What Food Safety Guidelines Say
The FDA recommends cooking beef, pork, veal, and lamb to a minimum internal temperature of 145°F (63°C) with a three-minute rest time. Ground meat, which includes many liver preparations, should reach 160°F (71°C). The FDA specifically notes that color and texture are unreliable indicators of safety, and that a food thermometer is the only reliable method.
No major food safety agency in the U.S. endorses eating raw liver. The nutrients in liver are available in cooked form, and cooking eliminates the bacterial, viral, and parasitic risks almost entirely. If the goal is maximizing iron absorption, cooking liver lightly (rather than well-done) preserves more heme iron while still reaching safe temperatures. Pairing liver with vitamin C-rich foods also boosts iron absorption without requiring you to eat it raw.
The Bottom Line on Raw vs. Cooked
Raw liver does contain more bioavailable iron and slightly higher levels of heat-sensitive nutrients than cooked liver. But the margin of benefit is modest compared to the risks. Cooked liver is still vastly more nutrient-dense than almost any other food. The pathogens found in raw liver, particularly hepatitis E in pork liver and bacteria across all types, represent concrete health threats that cooking eliminates. For most people, lightly cooked liver delivers nearly all the nutritional benefits with a fraction of the risk.