Nicotinamide/B3 gets surprisingly strong human glaucoma evidence

This audio article is from VisualFieldTest.com.Read the full article here: https://visualfieldtest.com/en/nicotinamide-b3-gets-surprisingly-strong-human-glaucoma-evidenceTest your visual field online: https://visualfieldtest.comSupport the show so new episodes keep coming: https://www.buzzsprout.com/2563091/supportExcerpt:Nicotinamide/B3 Gets Surprisingly Strong Human Glaucoma Evidence What the 2026 studies show about vitamin B3, nicotinamide, glaucoma prevention, neuroprotection, dosage and safety Introduction As of August 13, 2026, the evidence linking nicotinamide, a form of vitamin B3, with glaucoma protection has become substantially more persuasive—but it still has not crossed the threshold required to change routine treatment. Two new human studies are driving the renewed interest: A July 9, 2026, JAMA Ophthalmology cohort study found that patients with ocular hypertension who had documented systemic nicotinamide exposure were much less likely to receive a later diagnosis of primary open-angle glaucoma. An August 2026 American Journal of Ophthalmology analysis of the Rotterdam Study found that higher dietary intake of niacin, the broader vitamin B3 category, and vitamin B12 was associated with a lower risk of developing open-angle glaucoma. These findings reinforce earlier randomized trials showing that nicotinamide may improve certain measures of retinal function in people who already have glaucoma. They also fit a biologically plausible theory: aging, elevated eye pressure and oxidative stress may deplete nicotinamide adenine dinucleotide, or NAD+, leaving retinal ganglion cells less able to produce energy and survive stress. However, the most dramatic prevention result is observational, not randomized. High-dose nicotinamide also carries a real—although probably uncommon—risk of liver injury. The evidence is promising enough to justify large clinical trials, but not yet strong enough to replace pressure-lowering treatment or support unsupervised high-dose supplementation. () The central new finding: lower glaucoma conversion in ocular hypertension What the JAMA Ophthalmology study examined The study used deidentified electronic health-record data from 67 United States health care organizations, covering March 2006 through March 2026. Researchers identified people with ocular hypertension but no previous open-angle glaucoma, laser treatment or glaucoma eye-drop therapy. The analysis compared: 1,460 patients with documented systemic nicotinamide exposure 1,460 propensity-matched control patients with no recorded use of nicotinamide or niacin The groups were followed for an average of 3.7 years. The study was published online on July 9, 2026. () Primary open-angle glaucoma diagnosis A subsequent diagnosis of primary open-angle glaucoma occurred in: For the full table, please open this article on visualfieldtest.com. The reported hazard ratio of 0.34 corresponds to approximately a 66% lower hazard of diagnosis during follow-up. The absolute difference was 5.5 percentage points, with a 95% confidence interval of 3.8 to 7.3 percentage points. If the association were causal, a simple calculation would suggest that roughly 18 similar ocular-hypertension patients would need to receive nicotinamide to prevent one additional diagnosis over approximately four years. That number was not reported by the investigators and should not be interpreted as a treatment recommendation. () Fewer glaucoma treatments and laser procedures The study also found lower rates of treatment escalation: Topical eye-pressure-lowering treatment: 13.6% with nicotinamide versus 21.2% in controls Hazard ratio: 0.57 Laser trabeculoplasty: 0.8% with nicotinamide versus 1.9% in controls Hazard ratio: 0.38 These findings suggest that nicotinamide exposure was associated not only with fewer glaucoma diagnoses, but also with fewer downstream treatment decisions. However, medication initiation and laser treatment are influenced by clinician judgment, follow-up patterns, coding and patient preferences. They are useful supporting outcomes, but they are not direct measurements of retinal ganglion-cell survival. () Is the apparent effect unusually large? Numerically, yes. The size of the association is striking because it resembles the benefit of the best-established prevention strategy for ocular hypertension: lowering intraocular pressure. In the randomized Ocular Hypertension Treatment Study, five-year primary open-angle glaucoma incidence was: 4.4% in patients assigned to pressure-lowering eye drops 9.5% in patients assigned to observation That corresponded to a hazard ratio of approximately 0.40 and an absolute risk reduction of 5.1 percentage points. () The nicotinamide cohort reported: 3.5% versus 9.0% Hazard ratio 0.34 Absolute risk reduction 5.5 percentage points Therefore, the observed nicotinamide association was at least as large numerically as the Ocular Hypertension Treatment Study result. But the comparison is not proof that nicotinamide works as well as eye-pressure-lowering medication. The studies differed in several important ways: The Ocular Hypertension Treatment Study was randomized; the nicotinamide study was observational. The follow-up periods were different. The participants may have had different levels of baseline risk. The glaucoma outcomes were identified differently. The nicotinamide study did not provide the same detailed, standardized measurements of eye pressure, corneal thickness, optic-nerve appearance and visual fields. The correct interpretation is that the magnitude deserves urgent randomized testing, not that nicotinamide has already matched established treatment. Why the JAMA study cannot establish causation Propensity matching can make groups look similar using recorded information, but it cannot reproduce randomization. Several explanations other than a direct protective effect remain possible. Exposure was documented, not directly measured The study evaluated documented systemic nicotinamide exposure. Electronic records may not show: The actual dose The product formulation How long the patient took it Whether the patient took it consistently Whether the product was prescribed, purchased over the counter or obtained elsewhere A patient with a documented nicotinamide prescription may therefore differ considerably from a person taking a low-dose supplement intermittently. Residual confounding remains possible The records may not have fully captured important glaucoma risk factors, including: Family history Central corneal thickness Detailed baseline eye pressure Optic-nerve structure Visual-field status Genetic susceptibility Smoking, exercise and dietary patterns Health literacy and access to specialist care Even after statistical adjustment, unmeasured differences can remain. Healthy-user bias is a serious possibility People who take supplements may also be more likely to: Attend preventive medical visits Follow eye-care recommendations Exercise and eat a healthier diet Avoid smoking Seek care earlier Have better access to specialists Any of these factors could reduce the likelihood of glaucoma diagnosis or treatment escalation independently of nicotinamide. Diagnosis and treatment are not identical to disease biology A lower rate of glaucoma coding could reflect a lower rate of disease, but it could also reflect differences in: Follow-up frequency Provider documentation Testing intensity Access to glaucoma specialists Thresholds for labeling ocular hypertension as glaucoma Likewise, fewer prescriptions or laser procedures could reflect clinician preference rather than less retinal damage. The study did not prove a dose-response relationship A strong causal argument would be strengthened if higher doses, longer exposure or higher blood nicotinamide levels were associated with progressively greater protection. The available cohort result does not establish that relationship. The study did not prove an intraocular-pressure-independent effect The study did not establish whether nicotinamide users had lower eye pressure over time. It is therefore impossible to determine whether the association reflects: Direct retinal neuroprotection, Lower eye pressure, Better treatment adherence, Healthier behavior, or A combination of these factors. These limitations are especially important because the apparent benefit was large. Large effects from observational studies are valuable signals, but they are also particularly vulnerable to bias. () What the August 2026 Rotterdam Study adds The Rotterdam Study provides a different kind of evidence. Rather than examining high-dose supplements, investigators assessed usual dietary intake of several B vitamins in people initially free of open-angle glaucoma. The analysis included: 6,742 participants Mean age: 62.4 years 58.2% women 162 new cases of open-angle glaucoma The analysis adjusted for at least age, sex, total calorie intake, diet quality and follow-up time. () Niacin, or dietary vitamin B3 Higher dietary niacin intake was associated with lower incident open-angle glaucoma: Odds ratio per additional milligram per day: 0.94 Highest intake group: approximately 23.27 milligrams per day Lowest intake group: approximately 9.98 milligrams per day Highest versus lowest intake groups: odds ratio 0.43 Trend across groups: P = .02 This is consistent with a potentially protective role for vitamin B3-related nutrition. However, dietary niacin is not the same intervention as taking one to three grams of purified nicotinamide daily. Food-based measures generally combine different sources and forms of vitamin Support the show