Figure 7. Diagram showing the two pathways dietary nicotinamide can take before being converted into NAD

From

The Proposed Effects of Nicotinamide Adenine Dinucleotide (NAD) Supplementation on Energy Metabolism

Benjamin David French

American Journal of Sports Science and Medicine. 2015, 3(5), 96-107 doi:10.12691/ajssm-3-5-3