Nicotinamide riboside tartrate, an orally active NAD + precursor, increases NAD + levels and activates SIRT1 and SIRT3. Nicotinamide riboside tartrate is a source of vitamin B3 (niacin) and enhances oxidative metabolism, protection against high fat diet-induced metabolic abnormalities. Nicotinamide riboside tartrate reduces cognitive deterioration in a transgenic mouse model of Alzheimer’s disease.