Nicotinic acid

Nicotinic acid (niacin, vitamin B3) is a water-soluble vitamin and direct precursor for nicotinamide adenine dinucleotide (NAD⁺/NADH), the central redox cofactor of cellular energy metabolism and mitochondrial oxidative phosphorylation. In saliva it reflects niacin status and the availability of NAD⁺ biosynthetic substrate underpinning exercise energy turnover. Ringseis et al. (2020) demonstrated that nicotinic acid availability enhances muscle oxidative adaptation and improves endurance performance.