Study · Nutrients · 2021Conflicts declared

Niacin intake and glaucoma in US adults

What it found

In a US survey, adults who ate more niacin were less likely to report having glaucoma or to show signs of it on retinal images.

The link was not seen with a stricter set of diagnostic criteria.

What they found

Studies in people

Self-reported glaucoma

People in the third and fourth quartiles of niacin intake (21.01 to 28.22 mg/day and more than 28.22 mg/day) were less likely to report having glaucoma than those in the lowest quartile. After adjusting for age, gender, total energy intake, race, education, and diabetes, the link was no longer significant.

Glaucoma on retinal images

The odds of glaucoma seen on fundus images were lower in the third and fourth quartiles of niacin intake. This remained significant after adjusting for age, gender, total energy intake, race, education, and diabetes.

Stricter criteria

When glaucoma was defined using the ISGEO criteria, which require both structural and visual field changes, there was no significant link with niacin intake.

Average niacin intake

The average daily niacin intake was 24.18 mg/day. People with self-reported glaucoma consumed less niacin on average (21.14 mg/day) than those without (24.35 mg/day).

Animal and lab studies

Animal and lab studies

In mice and rats, high doses of a related form of niacin (nicotinamide) protected the optic nerve. These doses were much higher than typical dietary intake in people.

What the authors conclude

“Greater niacin intake may be associated with a lower chance of developing glaucoma.”
Taechameekietichai T, Chansangpetch S, Peerawaranun P, Lin SC, 2021

Also in their conclusions

  • They conclude that greater niacin intake may be associated with a lower chance of developing glaucoma.
  • They suggest that a certain threshold of niacin dosage is required for the potential effect to be greatest.
  • They call for further research to determine the precise dose and time relationship for the best possible benefit to the optic nerve.

How it was done

The authors wanted to see whether niacin, a form of vitamin B3, is linked to glaucoma. They note that niacin is important for nerve cells and that restoring a related molecule, NAD, might protect the optic nerve.

They looked at data from 5768 people aged 40 and older who took part in the 2005 to 2008 National Health and Nutrition Examination Survey. Niacin intake came from two dietary interviews, and glaucoma was assessed by self-report, retinal imaging, and a stricter set of criteria.

What it can’t tell you

  • This was an observational study, so it cannot show that niacin causes a lower risk of glaucoma.
  • Glaucoma was mainly based on self-report, which may not always be accurate.
  • The study could not include eye pressure in the diagnosis, and niacin intake was based on dietary recall, which can be imprecise.

The paper

Title
Association between Daily Niacin Intake and Glaucoma: National Health and Nutrition Examination Survey
Type
Study
Evidence
Studies in people · animals · lab
Summarised from
Full text
Cite
Taechameekietichai T, Chansangpetch S, Peerawaranun P, Lin SC (2021). Association between Daily Niacin Intake and Glaucoma: National Health and Nutrition Examination Survey. Nutrients. doi:10.3390/nu13124263Free full textPubMed 34959814DOI

Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error