Vitamin B3 and Glaucoma: Could It Help Protect the Optic Nerve?
Glaucoma is one of the leading causes of irreversible vision loss worldwide. What makes it particularly concerning is that many people experience no obvious symptoms during its early stages.
The condition damages the optic nerve, which carries visual information from the eye to the brain. Vision loss often begins in the peripheral field, making it possible for someone to have significant damage before noticing a change.
High pressure inside the eye, known as intraocular pressure (IOP), is an important risk factor. However, glaucoma can also progress in people whose eye pressure is within the statistically normal range.
This has encouraged researchers to look beyond pressure control and investigate whether protecting the nerve cells themselves could offer another way to slow the disease.
One area attracting attention is nicotinamide, a form of vitamin B3.
Why Are Scientists Studying Vitamin B3?
The retina contains specialised nerve cells called retinal ganglion cells. Their long fibres come together to form the optic nerve, making it possible for visual signals to travel to the brain.
Like other nerve cells, they need a steady supply of energy to function. Researchers believe that problems involving cellular energy production and mitochondria—the structures that help cells generate energy—may contribute to retinal ganglion cell damage in glaucoma.
Nicotinamide is involved in the production of NAD+, a molecule that plays an essential role in cellular energy metabolism and several repair processes.
This has led scientists to investigate whether increasing nicotinamide availability could help stressed retinal cells maintain their function.
The idea is promising, but it remains an area of active research rather than an established treatment.
What Did the Clinical Trials Discover?
A notable study published in Clinical & Experimental Ophthalmology in 2020, led by researcher Flora Hui and colleagues, examined nicotinamide supplementation in 57 people with glaucoma.
Participants received either a placebo or nicotinamide alongside their existing glaucoma treatment. The researchers used electroretinography, a test that measures electrical responses in the retina.
The study found improvements in certain measures of inner retinal function among participants receiving nicotinamide. However, it was a relatively small, short-term trial. It did not establish that the supplement prevents long-term vision loss or reverses permanent optic nerve damage.
Another phase 2 clinical trial, published in JAMA Ophthalmology in 2022, investigated a combination of nicotinamide and pyruvate. Researchers reported a greater number of improving visual-field test locations in the treatment group than in the placebo group over a median follow-up of approximately 2.2 months.
The findings were encouraging, but the researchers emphasised the need for longer studies to determine whether these changes translate into lasting protection against glaucoma progression.
What Is the Latest Research Telling Us?
The research has moved beyond small preliminary studies.
A major phase 3 study, known as the Nicotinamide in Glaucoma (NAMinG) trial, is investigating whether nicotinamide can slow visual-field deterioration in people with open-angle glaucoma. Its planned enrolment is approximately 496 participants.
A separate phase 3 study is examining nicotinamide combined with calcium pyruvate in people who continue to receive standard glaucoma care. Researchers are assessing changes in visual-field function and retinal structure over a longer period.
These trials are important because an improvement in a short-term electrical test is not necessarily the same as preserving useful vision over several years.
Until longer-term results are available, nicotinamide should be considered investigational for glaucoma.
Why High-Dose Vitamin B3 Is Not a Harmless Shortcut
It is tempting to assume that because vitamin B3 is an essential nutrient, taking more of it must be beneficial. That assumption can be dangerous.
The amounts investigated in glaucoma research are far higher than ordinary dietary requirements. High-dose nicotinamide can cause adverse effects, and there have been reports of serious liver injury during supplementation research.
The American Academy of Ophthalmology and American Glaucoma Society issued guidance in 2025 warning against unsupervised high-dose use. Their position highlights the need for medical oversight and liver-function monitoring when considering nicotinamide supplementation. They also advise against high-dose use in people with current or previous liver disease.
It is also important to distinguish nicotinamide from nicotinic acid, commonly called niacin. Both are forms of vitamin B3, but they are not interchangeable, and their effects and safety profiles differ.
A regular balanced diet can provide vitamin B3 through foods such as poultry, fish, peanuts, mushrooms and whole grains. However, obtaining enough B3 through food is not the same as taking pharmacological doses for a medical condition.
Do not start high-dose supplements to treat glaucoma without specialist medical advice.
Why Eye Pressure Treatment Still Matters
Despite growing interest in neuroprotection, lowering intraocular pressure remains the established approach to slowing glaucoma progression.
Depending on the individual, treatment may include prescription eye drops, laser procedures or surgery. These approaches aim to reduce pressure-related stress on the optic nerve.
People with glaucoma should continue their prescribed treatment even if they are interested in emerging vitamin research. Stopping medication without an ophthalmologist’s advice can put vision at risk.
Regular examinations are equally important. Eye-pressure measurements, visual-field tests and optical coherence tomography (OCT) scans help specialists monitor changes and adjust treatment when necessary.
Protecting Vision Starts With Early Detection
Glaucoma damage is often permanent, which makes early diagnosis particularly important. People with a family history of glaucoma or other recognised risk factors should discuss appropriate eye examinations with an eye-care professional.
If you have already been diagnosed, attending follow-up appointments and following your treatment plan are among the most important steps you can take.
The research into vitamin B3 offers a hopeful new direction. It suggests that supporting the health and energy metabolism of retinal nerve cells may eventually complement traditional pressure-lowering treatment.
But the evidence is not yet strong enough to call nicotinamide a glaucoma therapy.
For now, the best approach is to protect vision through early detection, consistent medical care and a healthy lifestyle while allowing well-designed clinical trials to establish whether vitamin B3 has a lasting role in eye health.
Photo by Amel Uzunovic: https://www.pexels.com/photo/close-up-of-a-blue-eye-with-detailed-eyelashes-35451422/
About Wellcore Weekly: Wellcore Weekly covers health, wellness, nutrition, sleep, fitness, and medical research with timely, easy-to-understand updates for everyday readers.
