You can think of pathways like conveyor belts in a factory. As the raw material moves along the conveyor belt, it is molded, stripped for parts, and tweaked until becomes a different molecule entirely. In this case, the new molecule is NAD+. The three pathways3 that NAD+ is made through is Preiss-Handler, Salvage, and De Novo Biosynthesis pathways. And since this process declines with age, getting enough of these precursors becomes incredibly important. Let’s look into the three NAD+ precursors here: As far as a NAD+ precursor, however, nicotinic acid requires too high levels to see a significant change in NAD+. This is because it takes multiple steps to turn it into NAD+ along the pathways7. And these high levels might come with side effects, like skin flushing (meaning your skin might be blotchy or inflamed). Naturally, it’s found in trace amounts of milk but not enough to do anything substantial when drunk. Your best bet? A supplement. And so far, NR supplements have been tolerated at doses as high as 1,000 mg12 per day in trials, suggesting that for most it’s likely safe. “Supplementing with NR can support NAD+ to maintain your mitochondria and ATP levels. One recent randomized, double-blind, placebo-controlled, crossover clinical trial found regularly supplementing with 500 mg of NR twice daily effectively stimulates NAD+ metabolism in healthy middle-aged and older adults13.
