Safety of Long-term use of (Nicotinamide Riboside Chloride)

[Kia17]

Nicotinamide riboside (NR) is a newly discovered nicotinamide adenine dinucleotide (NAD+) precursor vitamin. A crystal form of NR chloride termed NIAGEN is generally recognized as safe (GRAS) for use in foods and the subject of two New Dietary Ingredient Notifications for use in dietary supplements.

nature.com/articles/s41598-...

[Kia17]

Consumption of 100, 300 and 1000 mg NR dose-dependently and significantly increased whole blood NAD+ (i.e., 22%, 51% and 142%) and other NAD+ metabolites within 2 weeks.

[Kia17]

NR and plasma homocysteine

Nicotinamide N-methyltransferase catalyzes the transfer of a methyl group from S-adenosylmethionine (SAM) to NAM, generating to MeNAM and S-adenosylhomocysteine49,50,51. S-adenosylhomocysteine is then subsequently cleaved to homocysteine (HCY) and adenosine. It has been reported that single 300 mg oral doses of NA and NAM increase plasma HCY levels23, indicating a potential shortage of methyl groups that could be needed for formation of molecules such as dopamine and creatine. Moreover, increased plasma HCY is an independent risk factor for the development of vascular disease57,58,59. To determine whether prolonged ingestion of NR increases plasma HCY levels, a post hoc analysis was conducted using sodium citrate-treated plasma samples collected during the study. Compared to baseline or the placebo-treated group, NR ingestion had no effect on plasma HCY levels

[Kia17]

Recently, dose-dependent, statistically significant increases in total cholesterol and LDL-C were observed in a clinical study in which participants received a combination of 250 mg NR plus 50 mg pterostilbene or a combination of 500 mg NR plus 100 mg pterostilbene for eight weeks42. As shown in Table 4, there were no statistically significant differences in the NIAGEN and placebo-groups with respect to any clinical chemistry parameter. Clinical testing of pterostilbene alone indicates that it produces time and dose-dependent increases in human LDL-C53 of a magnitude that are a public health concern54,55 and are inconsistent with pterostilbene being a sirtuin 1 activator or included as part of a consumer wellness product56

[Kia17]

To minimize the effect of dietary influences on NAD+ metabolite levels, subjects were instructed to avoid foods that contain high amounts of tryptophan and forms of vitamin B3 during the run-in and NR supplementation periods.

[sharoncrayn]

Somewhat irrelevant CT for PD sufferers.

This CT did not address any critical issues for PD patients. It looked at "safety" for over weight healthy individuals. (were they diabetic?). Definitely no PD patients.

Therefore, objectively, we must assume "further research" of a long term, large scale CT is needed to prove NR's true efficacy for PD patients.

Plenty of studies on NR and NMN, so I would assume we can move on to examine it in relationship to PD. The NOPARK CT and their related CT hasn't even begun recruiting so it could be awhile.

The Niagen CT isn't published yet and has nothing to do with PD. No surprise.

Wake me up when we get to the real issues for PD and whether NR has a positive impact.

Sharon.