It’s no coincidence that the first three syllables of NAD+, nicotinamide, sound like nicotine. NAD+ is a form of vitamin B3 and was one of the first vitamins ever discovered. Nicotine, the addictive substance found in tobacco, interferes with absorption of nicotinamide and B3 in the body because of the similarity between the two molecules. If you’ve heard that smoking compromises the immune system, this is one of the reasons why. Geneticist David Sinclair from Harvard is one of the leading players in this field.
