Malic Acid Unit Converter

Malic acid (also called L-malate) is a naturally occurring organic acid and a key intermediate of the TCA cycle (also known as the Krebs cycle), the central energy-producing pathway in every cell.

In the TCA cycle, the enzyme fumarase converts fumarate into malate, which is then oxidized to oxaloacetate by malate dehydrogenase. This reaction generates NADH, a molecule that feeds the electron transport chain to produce ATP, the body's primary energy currency.

Measuring malic acid in blood helps evaluate how efficiently the TCA cycle is functioning. It is typically interpreted alongside other TCA cycle metabolites such as citrate, succinate, and fumarate rather than in isolation.

Malic acid is produced continuously in every cell as part of the TCA cycle, where fumarase converts fumarate into malate. Dietary sources also contribute, with apples being the richest (malic acid makes up about 90% of their organic acid content), along with tart cherries, grapes, tomatoes, and rhubarb.