Redox balance in every cell of human body is regulated by endogenous derivatives of vitamin B3 called pyridine nucleotides or NAD-metabolites (Xiao, et al., 2018; Ying, W.,2008). NAD-metabolites, namely NAD+, NADH, NADP+ and NADPH, function in pairs and mediate all the reactions requiring electron transfer. The NAD-metabolites are indispensable for cell function and the demand for them is high. Oxidized forms (NAD+ and NADP+) are well-established signalling molecules and oxidizing factors, while reduced forms (NADH and NADPH) constitute reductive power of the cell, such as in reductive biosynthesis, energy production and defence against oxidative stress (Pollack et al., 2007).
NADmed is an assay that directly measures all four NAD-metabolites from one sample of blood, tissue or cells giving the full picture on NAD metabolism in the body. NADmed assay is easy and fast to perform; it is suitable for high-throughput screening in tissues and cells and could be connected to drug testing, prediction of vitamin B3 disbalance in the body in different pathologies, as well as a guidance for supplementation with high-doses of Vitamin B3 or supplementation with any other drugs affecting NAD metabolites/metabolism. NADmed assay is based on cyclic enzymatic reaction with colorimetric detection that requires as little as 100µl of blood or 10mg of tissue sample.
Comparison to other methods: Currently, there are no alternative methods that would quantitatively measure all forms of NAD. The gold standard for measurement of NAD/NADH is mass spectrometry which is expensive and not readily available in every laboratory.