Abstract—: Nicotinamide adenine dinucleotide (NAD) plays a key role in the vital metabolic and regulatory processes in mammals. Disturbance of the NAD level regulation is associated with the development of such serious diseases as pellagra, neurodegenerative and cardiovascular disorders, diabetes, cancer and others. This paper presents an experimental approach that allows to determine the amount of NAD⁺ in mouse tissues using NMR spectroscopy, as well as the level of NAD⁺-dependent deacetylation of proteins in the cytosol and mitochondria.