This study investigated the effect of nicotinamide (NAM) supplementation on the development of brain inflammation and microglial activation in a mouse model of type 1 diabetes mellitus...The NAD+ content was increased in the brains of NAM-treated mice compared with untreated diabetic mice...Dietary NAM supplementation in diabetic T1D mice prevented brain inflammation via NAD+-dependent deacetylation mechanisms, suggesting an increased action of sirtuin signaling.