Which foods or habits effectively raise NAD+ levels?

The strongest and most direct way to raise NAD+ levels is oral supplementation with nicotinamide riboside (NR). In a small randomised double-blind crossover study in patients with Werner syndrome (a rare form of accelerated ageing), 1000 mg of NR per day demonstrably raised NAD+ levels, also improved arterial stiffness and skin ulcers, without serious side effects. For healthy people the clinical data are more limited, but broader review literature also reports positive effects, alongside findings from animal models.

Nicotinamide mononucleotide (NMN) acts as a direct precursor to NAD+ and shows protective effects in cell and animal research against, among other things, inflammation and diabetes. In humans the evidence is currently too sparse for firm recommendations. NMN is promising enough to take seriously, but it is still at an early stage of clinical research.

Niacin (vitamin B3) and related compounds are proven precursors of NAD+. In fatty liver disease, NAD+ levels are reduced and there are indications from preliminary research that niacin derivatives may be protective, but human studies show mixed results. Milk proteins contain the amino acid tryptophan, which can contribute to NAD+ production via a multi-step pathway, but how large this effect is in practice cannot be established firmly on the basis of the available literature. During pregnancy, adequate vitamin B3 and tryptophan are especially important: deficiencies have been linked in mouse models to serious congenital abnormalities, and in humans, genetic variants in NAD+ biosynthesis have also been linked to congenital abnormalities.

The NAD+ content of ordinary foods such as vegetables, meat, milk and fermented beverages does contain small amounts of NMN and NR, but their contribution to NAD+ status in the body has been almost entirely unstudied. You cannot rely on regular diet alone to raise NAD+ levels significantly.

Two habits deserve extra attention, but as risk factors. Eating too many simple sugars rapidly lowers NAD+ levels in cell-culture experiments and in young mice, with the added effect of disrupted bone formation. These are not yet direct human studies, but they represent a cautionary signal that a high-sugar diet can actively undermine NAD+. Intensive exercise in older adults has a mixed effect: muscle contraction increases NAD+ consumption, but whether that results in higher or lower levels on balance depends on how well production keeps up. In older adults that production capacity is reduced, so heavy exercise without adequate nutrition can deplete NAD+ stores further.