Clinical trials show oral bioavailability for nicotinamide riboside in humans and mice

In the first controlled clinical trial of nicotinamide riboside (NR), a newly discovered form of Vitamin B3, researchers have shown that the compound is safe for humans and increases levels of a cell metabolite that is critical for cellular energy production and protection against stress and DNA damage.

Studies in mice have shown that boosting the levels of this cell metabolite–known as NAD+–can produce multiple health benefits, including resistance to weight gain, improved control of blood sugar and cholesterol, reduced nerve damage, and longer lifespan. Levels of NAD+ diminish with age, and it has been suggested that loss of this metabolite may play a role in age-related health decline.

These findings in animal studies have spurred people to take commercially available NR supplements designed to boost NAD+. However, these over-the-counter supplements have not undergone clinical trials to see if they work in people.

The new research, reported Oct. 10 in the journal Nature Communications, was led by Charles Brenner, PhD, professor and Roy J. Carver Chair of Biochemistry at the University of Iowa Carver College of Medicine in collaboration with colleagues at Queens University Belfast and ChromaDex Corp. (NASDAQ: CDXC), which supplied the NR used in the trial. Brenner is a consultant for ChromaDex. He also is co-founder and Chief Scientific Adviser of ProHealthspan, which sells NR supplements under the trade name Tru NIAGENĀ®.

The human trial involved six men and six women, all healthy. Each participant received single oral doses of 100 mg, 300 mg, or 1,000 mg of NR in a different sequence with a seven-day gap between doses. After each dose, blood and urine samples were collected and analyzed by Brenner’s lab to measure various NAD+ metabolites in a process called metabolomics. The trial showed that the NR vitamin increased NAD+ metabolism by amounts directly related to the dose, and there were no serious side effects with any of the doses.

“This trial shows that oral NR safely boosts human NAD+ metabolism,” Brenner says. “We are excited because everything we are learning from animal systems indicates that the effectiveness of NR depends on preserving and/or boosting NAD+ and related compounds in the face of metabolic stresses. Because the levels of supplementation in mice that produce beneficial effects are achievable in people, it appears than health benefits of NR will be translatable to humans safely.”

The next step will be to study the effect of longer duration NR supplementation on NAD+ metabolism in healthy adults, but Brenner also has plans to test the effects of NR in people with diseases and health conditions, including elevated cholesterol, obesity and diabetes, and people at risk for chemotherapeutic peripheral neuropathy.

Publication: Nicotinamide riboside is uniquely and orally bioavailable in mice and humans.
doi:10.1038/ncomms12948
Adapted from press release by University of Iowa Health Care