It is theorised that vitamin B3 might be able to slow aging by increasing levels of a molecule called nicotinamide adenine dinucleotide (NAD). NAD levels decline with age, and preliminary evidence suggests that restoring NAD may reverse some aspects of ageing.
Studies suggest that vitamin B3 can normalise blood lipid levels in people with high LDL cholesterol or low HDL cholesterol. However, a meta analysis of 35 760 subjects found no beneficial effect for vitamin B3 in the treatment of cardiovascular disease.
Some studies report that application of vitamin B3 can improve the appearance of aging skin.