Niacinamide probably does not need in introduction to the people reading my posts. However, despite the multitude of animal studies demonstrating beneficial effects of this vitamin in virtually every chronic condition (and especially conditions associated with disturbed glucose metabolism), human studies with it are very scarce. The study below is one of those rare human ones, and it demonstrated that daily intake of nicotinamide mononucleotide (NMN), a metabolite of niacinamide and a direct recursor to NAD, improved glucose metabolism in postmenopausal women with prediabetes (the majority of whom were obese). The daily dosage of NMN was just 250mg and the trial lasted a little over 2 months (10 weeks). Animal studies suggest that higher doses of niacinamide, on the order of 1g-1.5g daily can actually reverse type II diabetes, but I guess for prevention purposes even 250mg would be a good start and when taken over a longer period of time may be able to alleviate even established diabetes. In addition to the benefits on glucose metabolism, the supplementation also changed favorably expression of genes involved in muscle synthesis and remodeling, which suggests niacinamide may also be relevant for other conditions such as muscle loss (sarcopenia, cachexia) often seen in sick and/or old people.
https://science.sciencemag.org/content/early/2021/04/21/science.abe9985
https://www.lifespan.io/news/nmn-human-trial-suggests-improved-muscle-glucose-metabolism/
https://www.eurekalert.org/pub_releases/2021-04/wuso-aci042021.php
“…A natural compound previously demonstrated to counteract aspects of aging and improve metabolic health in mice has clinically relevant effects in people, according to new research at Washington University School of Medicine in St. Louis. A small clinical trial of postmenopausal women with prediabetes shows that the compound NMN (nicotinamide mononucleotide) improved the ability of insulin to increase glucose uptake in skeletal muscle, which often is abnormal in people with obesity, prediabetes or Type 2 diabetes. NMN also improved expression of genes that are involved in muscle structure and remodeling. However, the treatment did not lower blood glucose or blood pressure, improve blood lipid profile, increase insulin sensitivity in the liver, reduce fat in the liver or decrease circulating markers of inflammation as seen in mice. The study, published online April 22 in the journal Science, is the first randomized clinical trial to look at the metabolic effects of NMN administration in people. Among the women in the study, 13 received 250 mg of NMN orally every day for 10 weeks, and 12 were given an inactive placebo every day over the same period.”
“…NMN is involved in producing an important compound in all cells, called nicotinamide adenine dinucleotide (NAD). NAD plays a vital role in keeping animals healthy. Levels of NAD decline with age in a broad range of animals, including humans, and the compound has been shown to contribute to a variety of aging-associated problems, including insulin resistance in studies conducted in mice. Supplementing animals with NMN slows and ameliorates age-related decline in the function of many tissues in the body.”