A large new analysis has renewed interest in an unlikely tool for protecting eyesight: vitamin B3. Published in JAMA Ophthalmology, the study reports that adults with ocular hypertension who took nicotinamide — a form of vitamin B3 — were 66% less likely to develop primary open-angle glaucoma over roughly four years than those who did not. The finding lands in a field long dominated by eye drops and laser therapy, and it points to a broader shift in how researchers are thinking about protecting the optic nerve.
What the New Study Found
Researchers reviewed electronic medical records from 67 U.S. healthcare organizations, identifying about 2,900 adults with ocular hypertension — elevated pressure inside the eye — but no glaucoma diagnosis. Half of the group had received nicotinamide supplementation; the other half had not. During an average follow-up of 3.7 years, 51 people in the nicotinamide group developed primary open-angle glaucoma (POAG) compared with 132 in the comparison group.
Beyond the headline 66% risk reduction, the analysis noted:
- A 43% drop in new prescriptions for intraocular pressure-lowering eye drops.
- A 62% drop in the use of laser trabeculoplasty, a procedure used to improve fluid drainage inside the eye.
The National Eye Institute describes glaucoma as a group of eye diseases that damage the optic nerve and can lead to irreversible vision loss. Open-angle glaucoma is the most common form in the United States, and roughly half of people with the disease do not know they have it. Because early damage is silent and existing therapies do not restore lost sight, any intervention that lowers the odds of developing the disease in the first place is significant.
Why Vitamin B3? The NAD+ Connection
Nicotinamide is the amide form of vitamin B3 and a precursor to nicotinamide adenine dinucleotide, better known as NAD+. NAD+ is a coenzyme central to how cells produce energy, repair DNA, and manage oxidative stress. Levels decline with age, and researchers increasingly link that decline to neurodegenerative conditions.
The retina and optic nerve are metabolically demanding tissues. Retinal ganglion cells — the neurons whose axons make up the optic nerve — are especially sensitive to mitochondrial dysfunction. Preclinical research at institutions including the National Institutes of Health has shown that boosting NAD+ with nicotinamide can strengthen these cells against pressure- and age-related injury in animal models of glaucoma. The JAMA Ophthalmology analysis is an observational look at whether that laboratory signal appears to translate to real-world patients.
Important Limits of the Evidence
Even a striking 66% figure deserves careful reading. The study is observational, meaning researchers looked at what happened in medical records rather than randomly assigning people to a supplement or a placebo. That design cannot prove cause and effect. People who take supplements often differ from those who do not — in income, health behaviors, or access to eye care — and those differences can influence outcomes.
Other caveats matter as well:
- No standard dose was documented. Earlier clinical trials of nicotinamide for glaucoma have tested doses up to 3 grams per day, well above typical over-the-counter B3 products, which usually range from 500 to 1,500 mg. The size of the effect could depend heavily on dose.
- Follow-up was under four years. Glaucoma develops over decades. Longer trials are needed to know whether the benefit holds up and whether vision itself — not just the diagnosis — is protected.
- The population was specific. Participants already had ocular hypertension, a known risk factor for glaucoma. Whether nicotinamide would help low-risk adults is a separate question.
Speaking to Medical News Today, ophthalmologist Dr. Benjamin Bert cautioned that even non-prescription treatments carry risks, including drug interactions and, at high doses, liver toxicity. Dr. Ariana Levin similarly urged patients to discuss any supplementation with their primary care physician before starting.
Vitamin B3 in the Diet and in Supplements
Nicotinamide and its close cousin nicotinic acid (niacin) are both forms of vitamin B3. The two behave differently in the body: nicotinic acid can cause facial flushing and, at pharmacologic doses, affects cholesterol; nicotinamide typically does not. Food sources of B3 include:
- Poultry, beef, and fish such as tuna and salmon
- Whole grains, brown rice, and fortified cereals
- Peanuts, sunflower seeds, and legumes
- Mushrooms and avocado
The National Institutes of Health Office of Dietary Supplements sets the Recommended Dietary Allowance for adults at 14 to 16 mg of niacin equivalents per day. Typical Western diets easily meet that target, so deficiency is uncommon in healthy adults. The doses used in glaucoma research are far higher and enter territory where side effects — nausea, elevated blood sugar, altered liver enzymes — become more likely. Higher-dose nicotinamide should not be treated as an everyday multivitamin decision.
What This Means for Eye Health Today
The most important takeaway is not that a supplement can replace standard glaucoma care. It cannot. Pressure-lowering drops, laser therapy, and regular dilated eye exams remain the foundation of care recommended by the American Academy of Ophthalmology and the National Eye Institute. Instead, the findings add to a growing body of research suggesting that metabolic and mitochondrial health may play a real role in optic nerve resilience — and that this angle deserves rigorous clinical trials rather than off-label experimentation.
Several randomized trials of nicotinamide for glaucoma and related optic nerve diseases are underway. Until their results are in, evidence-based steps for protecting vision include:
- Getting a comprehensive dilated eye exam on the schedule your eye care provider recommends, especially after age 40 or with a family history of glaucoma.
- Managing systemic risk factors such as blood pressure, blood sugar, and sleep apnea, all of which research links to optic nerve stress.
- Eating a diet rich in leafy greens, colorful vegetables, and omega-3-rich fish — patterns linked in observational studies to lower rates of age-related eye disease.
- Not smoking, and protecting the eyes from prolonged, unfiltered UV exposure.
Vitamin B3 research is a reminder that the science of vision protection is moving beyond eye pressure alone. But it is also a reminder that new findings, however striking, are usually the start of a longer investigation — not the end of one.
Disclosure: This content is for informational purposes only and is not medical advice. Always consult a qualified healthcare provider before making changes to your health regimen.