Niacinamide (a form of B3) is involved in NAD+ production, which is crucial for cellular energy and DNA repair.

Bogan, K. L., & Brenner, C. (2008). "Nicotinic acid,
nicotinamide, and nicotinamide riboside: A molecular evaluation of NAD+ precursor vitamins in human nutrition." Annual Review of Nutrition, 28, 115-130.

Potential neuroprotective effects in Alzheimer’s disease and age-related cognitive decline.

Liu, D., et al. (2021). "Nicotinamide supplementation in
neurodegenerative diseases: A review of clinical and preclinical studies." Neuroscience & Biobehavioral Reviews, 129, 179-194.