What do they do?
Extracts of beef (bovine) liver are a rich natural source of many vitamins and minerals, including iron.
Liver extracts provide the most absorbable form of iron—heme iron—and other nutrients critical in building blood, including vitamin B12 and folic acid. Liver extracts can contain as much as 3–4 mg of heme iron per gram. In addition to its use as a source of iron, liver extracts are also used by some healthcare practitioners to support liver function and boost energy levels. Liver extracts have been tested in people with chronic liver disease. However, no clear benefit has been demonstrated.1 2
Where are they found?
Liver extracts are available as nutritional supplements in capsules and tablets
Who is likely to be deficient of liver extracts?
As it is not an essential nutrient, no deficiency state exists.
How much liver extracts is usually taken?
The recommended amount depends on the concentration, method of preparation, and quality of the liver extract.
Are there any side effects or interactions with liver extracts?
No side effects or adverse reactions have been reported. Liver extracts should not be used by people suffering from iron-storage disorders, such as hemochromatosis.
As the liver is a major filtering organ for many potentially toxic environmental chemicals, some doctors are concerned that consumption of liver extracts may result in increased intake of these chemicals.
At the time of writing, there were no well-known drug interactions with liver extracts.