What is the primary source for gluconeogenesis in the liver?

The primary source for gluconeogenesis in the liver is amino acids. During gluconeogenesis, the liver synthesizes glucose from non-carbohydrate precursors, and amino acids play a crucial role in this process.

When the body is in a fasting state or when carbohydrate intake is low, glucagon levels rise, promoting gluconeogenesis. Amino acids, particularly those derived from the breakdown of proteins, are converted into intermediates that can eventually lead to glucose production. For instance, specific amino acids like alanine and glutamine can be directly utilized in gluconeogenesis.

While fatty acids and carbohydrates can also influence glucose production, fatty acids primarily undergo beta-oxidation to produce energy and are not a direct source for glucose synthesis. Carbohydrates, such as glycogen, can be quickly mobilized to release glucose but are not the main substrates for gluconeogenesis. Vitamins do not serve as precursors in the gluconeogenesis pathway. Thus, amino acids are essential for generating glucose in the liver, especially during periods when glycogen stores are depleted.