In a discovery that could transform the treatment of one of the world's most common liver conditions, an international team of researchers has found that vitamin B3 — a supplement available at virtually any pharmacy — can shut down a key genetic mechanism driving fatty liver disease.
The study, published in Metabolism: Clinical and Experimental, identifies microRNA-93 (miR-93) as a central regulator in metabolic-associated fatty liver disease (MASLD), a condition that affects roughly 30 percent of the global population. It is the first time this particular molecule has been clearly linked to how the disease develops and progresses.
Cracking the Genetic Code
Led by Professor Jang Hyun Choi at South Korea's Ulsan National Institute of Science and Technology (UNIST), in collaboration with researchers at Pusan National University and Ulsan University Hospital, the team discovered that levels of miR-93 are abnormally elevated in both human patients with fatty liver disease and in animal models of the condition.
Their analysis revealed a cascade effect: miR-93 drives fat buildup, inflammation, and scarring in the liver by suppressing SIRT1, a gene that plays a crucial role in managing fat metabolism within liver cells. When the researchers used gene editing to block miR-93 production in mice, the animals showed significantly less fat accumulation, improved insulin sensitivity, and better overall liver function. Conversely, mice engineered to overproduce miR-93 developed more severe metabolic problems.
A Vitamin Steps Into the Spotlight
With the genetic target identified, the researchers turned to an innovative strategy: drug repurposing. They screened 150 FDA-approved compounds to identify any that could reduce miR-93 levels. The winner was niacin — vitamin B3 — a substance that has been safely used for decades to manage cholesterol.
In mice treated with niacin, miR-93 levels dropped sharply while SIRT1 activity increased. This helped restore normal fat-processing pathways in the liver and improved overall lipid balance. The results suggest that a common, inexpensive vitamin could become a powerful new weapon against a disease that currently has limited treatment options.
Why This Matters
Fatty liver disease has quietly become one of the defining health challenges of the 21st century. Driven by modern diets and sedentary lifestyles, MASLD can progress from simple fat accumulation to inflammation, scarring, and eventually cirrhosis or liver cancer. Despite its prevalence, no targeted therapies have been widely adopted.
"This study precisely elucidates the molecular origin of MASLD and demonstrates the potential for repurposing an already approved vitamin compound to modulate this pathway," the research team explained. "Given that niacin is a well-established and safe medication used to treat hyperlipidemia, it holds promise as a candidate for combination therapies targeting miRNA pathways in MASLD."
The significance of the repurposing approach cannot be overstated. Because niacin already has extensive safety data from decades of clinical use, the path from laboratory discovery to patient treatment could be considerably shorter than developing an entirely new drug from scratch.
What Comes Next
While the results are promising, the researchers emphasize that clinical trials in human patients are the essential next step. The mouse models provide strong evidence, but human biology is complex, and dosing, timing, and potential interactions with other treatments all need to be carefully studied.
Still, the fundamental finding — that a safe, inexpensive, and widely available vitamin can target a newly identified genetic driver of a disease affecting nearly one in three people — represents exactly the kind of practical breakthrough that medical research strives for. Sometimes the most powerful medicines are the ones that have been on pharmacy shelves all along.
