The liver is a powerhouse of biochemical reactions, propelled by enzymes to accomplish liver function. An enzyme is a molecule that promotes a specific compound or effect, but the enzyme itself remains unchanged. Vitamins and minerals act as cofactors, assisting enzymes in liver functions, such as detoxification of toxins in the blood, glucose and glycogen regulation, synthesis of blood proteins, and bile and lipoprotein production.
Detoxification of Blood
Little can enter the blood circulation from the digestive tract unless substances first pass through the liver's detoxification process. A healthy liver eliminates unnatural compounds, such as food colorings, weed killers, medications, alcohol and also excess estrogen from the blood. The liver detoxifies the blood through two complex phases. Phases I and II change fat-soluble substances into water-soluble substances that can be excreted from the body.
Vitamins and minerals assist in those pathways. Vitamins to promote liver function in Phase I are vitamins B2, B3, B6, B12, folic acid, beta-carotene, vitamin C and vitamin E. Minerals to promote liver function in Phase I are copper, manganese, selenium and zinc. Phase II liver detoxification requires the mineral, sulfur. A variety of sulfur compounds can serve as sulfur donors. Sulfur-containing foods are garlic, onions and cruciferous vegetables, such as broccoli.
Glucose and Glycogen Regulation
The liver uses the mineral chromium and an amino acid, glutathione to create glucose tolerance factor that acts with insulin to regulate blood sugar levels. Then liver cells remove excess glucose and join glucose molecules together to form glycogen, which is stored for future energy needs. Glycogen production is performed by a series of reactions that require enzymes and vitamins B5 and biotin to work. The minerals magnesium, manganese and zinc assist in the enzymatic reactions.
The plasma proteins, prothrombin and fibrinogen, essential for blood clotting are synthesized by the liver. Vitamin K stimulates the liver to synthesize prothrombin for the blood, leading to faster clot formation when clotting is needed. Vitamin K is available in dark green leafy salads. The mineral calcium also helps one of the steps for blood clotting.
The liver makes bile and stores it in the gallbladder. After a meal, the gallbladder releases bile into the first segment of the small intestine. There bile emulsifies ingested fat into small water-soluble globules, accessible to lipase, an enzyme that splits the globules further into fatty acids, which are then absorbed into the blood. Bile production and secretion were normalized by vitamin E and the mineral selenium in rats poisoned by carbon tetrachloride.
Components of fat are assembled by the liver into lipoproteins. They include low-density lipoproteins, LDL, which are high in cholesterol and high-density lipoproteins, HDL, rich in protein. The blood transports LDL and HDL to areas that need the components and releases them for use. Ingesting vitamin C may lower total cholesterol values. The mineral calcium may increase the conversion of cholesterol to bile acids, thus lowering blood cholesterol numbers.
During Phase I of detoxification, free-radicals are created. Those molecules with unpaired electrons damage cells when they grab electrons out of cell membranes. The antioxidant vitamins A, C and E will stifle free-radicals. The minerals selenium and zinc also possess antioxidant power. Consuming antioxidants, whether by supplements or food, will promote healthy liver function.