NAD + yog ib qho tseem ceeb coenzyme hauv cov txheej txheem ntawm lub neej, ua lub luag haujlwm tseem ceeb hauv cov metabolism hauv lub zog, kho DNA thiab tiv thaiv kev laus, kev ntxhov siab ntawm tes thiab cov teeb liab tswj, nrog rau kev tiv thaiv neuroprotection. Hauv lub zog metabolism, NAD + ua haujlwm ua lub luag haujlwm tseem ceeb hauv glycolysis, lub voj voog tricarboxylic acid, thiab mitochondrial oxidative phosphorylation, tsav ATP synthesis thiab muab lub zog rau kev ua haujlwm ntawm tes. Nyob rau tib lub sijhawm, NAD + ua haujlwm tseem ceeb hauv substrate rau DNA kho enzymes thiab activator ntawm sirtuins, yog li tswj kev ruaj ntseg ntawm genomic thiab ua rau lub neej ntev. Nyob rau hauv cov xwm txheej ntawm oxidative kev nyuaj siab thiab o, NAD + koom nrog hauv kev taw qhia txoj hauv kev thiab kev tswj hwm calcium los khaws cellular homeostasis. Nyob rau hauv lub paj hlwb, NAD + txhawb nqa mitochondrial muaj nuj nqi, txo oxidative puas, thiab pab ncua qhov pib thiab kev loj hlob ntawm cov kab mob neurodegenerative. Txij li thaum NAD + qib ib txwm poob qis nrog lub hnub nyoog, cov tswv yim los tswj lossis txhim kho NAD + tau lees paub tias yog qhov tseem ceeb rau kev txhawb nqa kev noj qab haus huv thiab kev laus qeeb.