1:What is Nicotinamide Riboside Chloride?

Nicotinamide Riboside Chloride is a newly appreciated form of Vitamin B3, with unique properties, it is a formal precursor of NAD+. 

Nicotinamide riboside (NR), first described in 1944 as a growth factor (Factor V) for Haemophilus influenza, and in 1951, NR, first investigated as a metabolic fate in mammalian tissues.

Famous patented Brand named NIAGEN?(Nicotinamide riboside chloride), produced by Chromadex, Inc. in 2003, aims to reverse signs of aging from inside your body.

2:What kind of food sources contains Nicotinamide Riboside Chloride?

The amounts of NR in food are minute, compared to a nutritional supplement, and what kind of food sources contain nicotinamide riboside (NR)?

2.1:.Cow milk

Cow milk usually have ～12 μmol NAD(+) precursor vitamins/L, of which 60% was present as nicotinamide, and 40% was current as NR.(conventional milk contained more NR than organic milk ), a study published by the University of Iowa, in 2016

2.2:.Yeast

An old study stated, "One inhibitory substance was isolated from yeast and was found to be nicotinamide riboside, it may have from NAD(P) during the preparation of yeast extracts, or from dietary yeast supplements during digestion in vivo." While there is no quantitative data on yeast

2.3:.Beer

The beer has a fair amount of carbs and drinking those in a liquid form like that will have a glycemic impact; various research papers have mentioned beer as being a food source of nicotinamide riboside.

Also, there may be trace amounts of NR like whey protein, mushrooms, etc.

For many people, dairy is off limits for other reasons. The nicotinamide riboside food sources might be useful, but are less efficient than NR supplement.

3:Why Nicotinamide Riboside Chloride (NR) designate as an authentic NAD+ precursor vitamin invertebrates?

Generally,there are five reasons to support it:

3.1. Haemophilus influenza, a flu-causing bacterium, which has no de novo pathway and cannot utilize Na or Nam, is strictly dependent on NR, NMN, or NAD+ for growth in the host bloodstream.

3.2. Milk is a source of NR.

3.3.NR protects murine DRG neurons in an ex vivo axonopathy assay via transcriptional induction of the nicotinamide riboside kinase (NRK) 2 gene.

3.4. Exogenously added NR and derivatives increase NAD+ accumulation in a dose-dependent fashion in human cell lines.

3.5. Candida glabrata, an opportunistic fungus that depends on NAD+ precursor vitamins for growth, utilizes NR during dissemin