Organ Meat · Liver

Food · Animal Foods · Red Meat

Connected to · 3

food source · 3

Vitamin A
The liver is where animals store vitamin A: cooked pork liver has about 5400 µg RAE per 100 g, against an adult recommended intake of 700–900 µg a day, so 50 g covers about three days. Keep portions small; the UK NHS advises against eating liver and liver products in pregnancy.
Mechanism · 2
Mechanism · A lifetime's stock
Animals store the vitamin A they eat in the liver. A piece of pork liver holds the preformed retinol, that is, ready-made vitamin A, that the pig built up; unlike beta-carotene, it is not converted only as the body needs it. That makes it extremely dense, and for people who are not short of vitamin A, eating a lot of it becomes a burden.
Safety · Keep the portion small
Cooked pork liver has about 5400 µg RAE per 100 g (raw liver about 6500; braising lowers it somewhat), while the US adult Recommended Dietary Allowance (RDA) is 700–900 µg RAE a day, so 50 g of cooked pork liver covers about three days. The UK NHS advises against eating liver and liver products in pregnancy, because the vitamin A in them can harm the baby. Do not stack pork liver with cod-liver oil or vitamin A supplements either, especially for children.
Iron
Liver is very rich in iron. Part of it is heme iron, which is absorbed several times more efficiently than the iron in plants and is barely held back by tea drunk with the meal; the stored part sits in ferritin. Cooked pork liver has about 17.9 mg of iron per 100 g.
Mechanism · 2
Mechanism · Iron guarded by the ring
The liver is one of the busiest organs at handling heme, so part of its iron is heme iron guarded by the porphyrin ring; the iron it keeps in store is mostly packed into ferritin. The polyphenols in tea cannot grab this kind of iron. The greens and beans on the same plate still bring unguarded non-heme iron, and that is the share vitamin C helps.
Numbers · How much iron a serving holds
Cooked pork liver has about 17.9 mg of iron per 100 g and raw liver about 23.3 mg, several times as much as red meat. For people short of iron it is one of the most efficient food sources; for people who already have enough, that density is a burden. Pregnancy is the exception, because liver is so high in vitamin A.
Vitamin B12
Animal liver is extremely high in B12, and one serving covers several days. But liver has almost no fiber, little calcium and not much vitamin C, so the rest of the plate still has to round out the meal.
Mechanism · 2
Mechanism · Nutrients mounted on protein
The B12, iron, copper and riboflavin in liver are not loose powder but finished parts already mounted on protein: iron sits in the heme ring, copper in copper-containing enzymes, riboflavin on its coenzymes. They are taken apart and absorbed step by step through ordinary digestion rather than released in the gut all at once, which may be one reason food is often gentler than a supplement at the same dose.
In practice · A serving of liver is not a meal
One serving of liver covers several days of B12. The more impressive the nutrient list, the easier it is to think this one meal is enough, when the opposite is true: liver has almost no fiber, little calcium and not much vitamin C, so the meal still needs vegetables and whole grains.

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Why organ meat is so nutrient-dense

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The liver is where an animal stores its vitamin A, so a small serving of liver can deliver several days' worth, and eating it often or in large amounts can push you into excess. That is the most important thing to know about eating organ meat, and the chapter on the vitamin A toxicity boundary explains why.

Organ meat, or offal, is every part of an animal other than muscle: liver, kidney, heart, tripe, brain, and intestine. Chinese kitchens have always used it — stir-fried pork liver, chicken liver, flash-fried kidney, soy-braised beef tripe, and spicy blood-and-offal stew.

What organ meats share is this: the harder an organ works, the denser its micronutrients. The liver takes molecules apart and builds new ones all day long, so one serving delivers vitamin A, iron, B12, folate, copper, and selenium together.

That same density is why a slightly large portion overshoots, and cholesterol and purines are not low either. Organ meat is neither a miracle food nor a poison; it is a good ingredient whose dose you need to know. Pregnancy calls for extra care: the UK NHS advises not eating liver or liver products while pregnant. If you get a severe headache, repeated vomiting, or blurred vision after eating a large amount of animal liver at once, get medical care immediately.

This story centers on liver; kidney, heart, tripe, and brain come up along the way, and the same logic applies to them.

Educational content, not medical advice — consult a clinician.

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