While Vibrant does not offer a direct measurement of NAD, measuring the organic acids in the Krebs Cycle Citric Acid Cycle can serve as surrogate markers for NAD production. In the Krebs cycle, NAD+ is reduced to NADH, which carries electrons to the respiratory chain
- NADH Production: The cycle directly produces NADH, which must be converted back into NAD+ in processes like oxidative phosphorylation. Therefore, levels of intermediates such as succinate, fumarate, and malate, which are linked to the generation of NADH, can indicate the functional status of NAD+ regeneration.
- Metabolite Levels: Metabolites like succinyl-CoA, oxaloacetic acid, and alpha-ketoglutarate are part of the cycle and are critical for the efficient functioning of the cycle and subsequent NADH production. Alterations in their concentrations can suggest changes in NAD+/NADH levels.
- Enzymatic Activity: Enzymes such as isocitrate dehydrogenase and alpha-ketoglutarate dehydrogenase are directly involved in reactions that produce NADH. Measuring the activity of these enzymes can provide insights into the rate of NADH production.
Thus, by measuring these markers, a provider could assess the activity of the Krebs Cycle Citric Acid Cycle and, by extension, the production and utilization of NAD/NADH within cells.