Researchers estimate that about 95 million people around the world are affected by glaucoma, a group of eye diseases that can cause damage to the optic nerve, potentially leading to vision loss.
Past studies show that consuming certain nutrients, such as omega-3 fatty acids, dietary nitrates, and vitamins A and C may help lower glaucoma risk.
Additionally, researchers have been investigating how a type of vitamin B3 called nicotinamide might help lower glaucoma risk as well.
Now, a new study published in the journal JAMA Ophthalmology reports that nicotinamide may help lower the risk of primary open-angle glaucoma (POAG) in people with ocular hypertension, a known risk factor for developing glaucoma.
For this study, researchers analyzed electronic medical record data from 67 United States healthcare organizations, encompassing about 2,900 people with ocular hypertension but had not yet received a glaucoma diagnosis.
Half of the participant group received nicotinamide supplementation, while the other control group did not.
After an average of 3.7 years, 51 participants of the nicotinamide group received a diagnosis of POAG, compared to 132 participants in the control group.
At the study’s conclusion, researchers found there was a 66% lower risk of developing POAG in participants taking nicotinamide, as well as a 43% reduction in rates of topical intraocular pressure–lowering therapy prescription and 62% reduction in laser trabeculoplasty surgery for glaucoma.
Currently, nicotinamide is not an approved treatment or prophylactic for glaucoma.
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While this is not thefirst study to look at nicotinamide and glaucoma risk, there are still questions regarding the safety of nicotinamide supplementation.
In March 2025, the American Glaucoma Society and the American Academy of Ophthalmology issued a joint statement regarding the safety of nicotinamide supplementation, as taking too much of nicotinamide can lead to liver damage.
According to the joint statement, ongoing clinical trials are using what are considered high doses of nicotinamide at 3 grams (g) per day. Typical nicotinamide dosage is much lower, between 500 milligrams (mg) to 1,500 mg per day.
Potential adverse effects of taking too much nicotinamide include gastrointestinal issues such as nausea and stomach pain, headaches, dizziness, and fatigue, and has the potential for more severe risk including liver toxicity, elevated blood sugar levels, and blood disorders.
Medical News Today spoke with Benjamin Bert, MD, a board-certified ophthalmologist at MemorialCare Orange Coast Medical Center in Fountain Valley, CA — who was not involved in this study — about these research findings.
Bert commented that while this study further supports that nicotinamide may be protective in regard to the development of glaucoma in high risk individuals, before starting any new supplements, it is important to discuss them with your physician.
“Even when a treatment does not require a prescription, there are still risks involved, including interactions with other medications or supplements that you are taking,” he explained. “With nicotinamide there can be liver toxicities at higher doses, so liver function tests may need to be monitored if you are using a higher dose.”
Ariana Levin, MD, an assistant professor in the Department of Ophthalmology at NYU Grossman School of Medicine — who was likewise not involved in this study — agreed.
“I recommend that patients who want to take supplements should discuss these with their primary care physician to ensure they are taking a dose that is reasonable to take along with the rest of their prescription medications and in the context of their general health,” Levin explained to MNT.
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“In general, supplements are not regulated in the same way prescription medications are, so patients need to be diligent in evaluating the product that they are buying from the shelf (or online),” she advised.
Since glaucoma causes irreversible damage, Levin said that finding new ways or preventing the disease is key.
“Ideally we prevent damage from occurring before a high-risk patient develops the disease, or at least prevent further damage while the disease is still mild,” she detailed. “Once a patient has glaucoma, they have that diagnosis for life. We can get glaucoma under control, but it isn’t a diagnosis that ‘goes away’.”
“This article is exciting because it focuses on early prevention,” Levin continued. “It also focuses on a potential therapy that doesn’t act by lowering eye pressure. Lowering eye pressure is the most important tool we have right now in treating glaucoma, but we need other tools as well.”
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As glaucoma is a blinding disease, Bert said any treatments that we can have to prevent the development, prevent the progression, or reduce the overall risk are highly beneficial.
“A treatment that allows our bodies to continue to function the way that they are supposed to, as is the hypothesis with vitamin B3, then that would be especially beneficial. Glaucoma can be a difficult disease to control, so it is important that research continues to look at it from many different aspects to help continue to develop new treatments.”
– Benjamin Bert, MD
For the next steps in this research, Bert said the biggest piece of information missing from this study was the dosage of nicotinamide that the study population was taking.
“The study categorized those that were taking any supplementation of vitamin B3 as having ‘exposure’ to nicotinamide,” he explained. “Thus, it would be highly beneficial to have additional studies explore the exact dosing that would be beneficial. Knowing a specific dosage would also allow for the appropriate recommendations for monitoring potential side effects.”
