News · Supplements
A vitamin B3 supplement tracked far less glaucoma in at-risk eyes
Among 2,920 matched patients with high eye pressure, those taking nicotinamide developed glaucoma at 3.5% against 9.0%. The design cannot prove the supplement caused it.
Based on a peer-reviewed matched cohort study in JAMA Ophthalmology
- Researchers searched records from 67 US health care organizations spanning 2006 to 2026, publishing in JAMA Ophthalmology.
- Patients had ocular hypertension, meaning raised eye pressure without glaucoma, and no prior glaucoma treatment.
- Matching produced 2,920 patients, 1,460 taking nicotinamide and 1,460 with no history of nicotinamide or niacin use.
- Over a mean 3.7 years, glaucoma was diagnosed in 51 nicotinamide patients (3.5%) versus 132 controls (9.0%).
- That works out to roughly two-thirds lower risk (HR, 0.34; 95% CI, 0.25-0.47).
- Secondary outcomes covered starting eye-drop therapy and needing laser treatment.
- Observational. People who take supplements differ systematically from people who do not, and matching cannot fix all of it.
- The authors call it a potential adjunctive strategy warranting further prospective investigation, not an established treatment.
Glaucoma is the leading cause of irreversible blindness worldwide. The only treatment anyone has is lowering eye pressure. A study in JAMA Ophthalmology asked whether a cheap vitamin tracks with fewer people developing it. The gap it found was large. The design is too weak to settle anything.
The authors set out the state of play: ocular hypertension is a primary risk factor for primary open-angle glaucoma, and systemic nicotinamide has emerged as a potential metabolic prophylactic intervention to prevent conversion; however, real-world evidence is lacking.
What was compared
The population was chosen well. Everyone had raised eye pressure without glaucoma, which is exactly the group in whom prevention would matter.
The study evaluated deidentified electronic medical record data from a federated research network of 67 US health care organizations between March 2006 and March 2026, with propensity score matching used to pair each supplement user against a similar non-user.
Patients with a primary diagnosis of ocular hypertension and at least one prior health care encounter were included, excluding those with history of open-angle glaucoma, laser therapy, or glaucoma topical therapies. So nobody was already being treated.
The exposure was documented systemic nicotinamide exposure, compared with a control group having no history of nicotinamide or niacin use, and the matched sample came to 2,920 patients (1,460 in each cohort), mean age around 54 and about 58% female.
The result
Over a mean follow-up of 3.7 years, glaucoma diagnosis occurred in 51 patients in the nicotinamide group (3.5%) compared with 132 patients in the control group (9.0%).
That is 0.34 on the study’s risk scale, with a range from 0.25 to 0.47. Roughly two-thirds lower, and the uncertainty range does not come close to no effect.
Why the number is less impressive than it looks
An effect that large from a vitamin should prompt suspicion rather than excitement, and the reason is who takes supplements.
The matching balances what is recorded: age, sex, diagnoses, visits. It cannot balance what is not. And the difference between someone who takes a daily eye supplement and someone who does not is mostly unrecorded. It runs through health literacy, income, worry about their eyesight, and how reliably they show up.
The direction of that bias is genuinely unclear here, which is worth saying. More engaged patients attend more eye appointments. More appointments should surface more glaucoma, not less. That works against the finding. But those same patients may also have had their eye pressure watched more closely, which would cut conversion for reasons unrelated to any vitamin.
The exposure definition is also loose. Documented nicotinamide exposure in a medical record tells you it was noted at some point. It does not tell you the dose, or for how long, or whether the tablets were taken.
Three point seven years is short for a disease that develops over decades, and the trials now running use doses far above ordinary supplement strength.
What the authors actually claim
They are careful, and the wording repays attention: systemic nicotinamide exposure was associated with a reduced risk of disease development in patients with ocular hypertension, and nicotinamide represents a potential adjunctive strategy complementary to standard therapy, warranting further prospective investigation.
Potential. Adjunctive. Complementary to standard therapy. Warranting further investigation. Four hedges in one sentence, and every one of them is doing work.
The practical position
This is a real signal in a real population. It is also the kind of signal that keeps failing to survive a randomized trial. Vitamin E for heart disease, beta-carotene for cancer, vitamin D for almost everything: all looked convincing in this sort of data, and then trials found nothing.
Randomized trials of nicotinamide in glaucoma are underway. Until they report, the sensible reading is that this is a promising lead worth watching, and not a reason to substitute a supplement for the eye drops that are the only treatment currently known to work.
People also ask
What is ocular hypertension and how does it relate to glaucoma?
Raised pressure inside the eye without any detectable damage to the optic nerve. It is the single biggest risk factor for primary open-angle glaucoma, which is the damage itself, but most people with raised pressure never convert. That makes it the ideal population for a prevention study: everyone is at risk, and only some progress.
What is nicotinamide and why would it protect the optic nerve?
A form of vitamin B3, sold widely as a supplement and distinct from niacin in that it does not cause flushing. The rationale is metabolic: retinal ganglion cells, the nerve cells that die in glaucoma, are unusually energy-hungry, and nicotinamide feeds into the cellular energy pathway. Laboratory work has shown protective effects, which is what prompted studies in people.
How much should a two-thirds reduction be trusted?
Less than the number suggests, because of the design. People who take a supplement for eye health differ from people who take nothing in ways records cannot capture: they are typically more engaged with healthcare, more health-conscious, and possibly more likely to attend appointments where a diagnosis would be made. Any of those could produce a large apparent benefit without the supplement doing anything.
Would that confounding push in a particular direction?
It could push either way, which is worth noting. Health-conscious people attend more eye appointments, and more appointments would tend to find more glaucoma, not less. That works against the observed result. But they may also be treated more aggressively for their eye pressure in the first place, which would reduce conversion for a reason unrelated to the vitamin.
Should anyone with high eye pressure start taking it?
This is general information rather than medical advice, and the honest answer is to ask an ophthalmologist rather than a website. Trials of nicotinamide for glaucoma are underway and the doses studied are far above what a standard supplement provides. High-dose vitamin B3 is not risk-free, with liver effects reported at high intakes. Nobody should substitute it for pressure-lowering treatment that is working.