Dietary niacin and diabetic retinopathy in US adults
What it found
In a survey of US adults with diabetes, those who ate more niacin in food were less likely to report diabetic retinopathy.
The link was found in people, not in animals or cells.
What they found
Studies in people
Higher niacin, less retinopathy
After accounting for all variables, each unit increase in dietary niacin was linked to a lower chance of having diabetic retinopathy. The association stayed stable across subgroups by age, sex, and smoking status.
Top quarter vs bottom quarter
People in the top quarter for niacin intake had a 31% lower likelihood of diabetic retinopathy than those in the bottom quarter. After full adjustment, the decrease was 28%.
Nonlinear link in men
In men, the relationship was not a straight line. Below an intake of 3.35 (10 mg), more niacin was linked to less retinopathy, but above that point there was no statistically significant link.
U-shaped patterns in some groups
U-shaped patterns were also seen in people younger than 60 and in smokers, with turning points at 4.35 (10 mg) and 2.21 (10 mg), but these were not statistically significant.
What the authors conclude
“In summary, this study reveals a negative correlation between dietary niacin intake and DR, providing preliminary evidence for incorporating dietary niacin into nutritional strategies for preventing DR.”
Also in their conclusions
- They say the findings provide preliminary evidence for including dietary niacin in nutritional strategies to prevent diabetic retinopathy.
- They note that dietary niacin is inexpensive and readily accessible, and that moderately increasing intake through daily diet may be a feasible strategy for eye health.
- They advise caution when intake approaches the tolerable upper intake level, as extra protective benefits may not occur and risks may rise.
How it was done
The authors wanted to fill a gap in knowledge about how niacin eaten in food, rather than taken as a supplement, relates to diabetic retinopathy in the general population. They hoped to support more sensible dietary guidelines.
They looked at data from 3,990 people with diabetes who took part in the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2018. Dietary niacin was estimated from two 24-hour food recall interviews, and diabetic retinopathy was based on whether a doctor had told them diabetes affected their eyes.
What it can’t tell you
- This was a cross-sectional study, so it can show a link but cannot prove that higher niacin intake causes less diabetic retinopathy.
- Dietary intake was based on memory of what was eaten, which can be inaccurate.
- The study cannot show the best dose of niacin or whether supplements work the same way as food sources.
Who paid
- Funding
- Funded by Shandong Provincial Traditional Chinese Medicine Science and Technology Project (No.M20241832). (from the PubMed record).
- Conflicts
- The authors have no conflicts of interest to disclose.
- Authors work at
- Shandong University of Chinese Medicine, China; Hunan University of Chinese Medicine, China; Shandong Hospital of Traditional Chinese Medicine, China
The paper
- Title
- Association of dietary niacin intake with diabetic retinopathy: A cross-sectional study
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Wang S, Li X, Chen M (2025). Association of dietary niacin intake with diabetic retinopathy: A cross-sectional study. Medicine. doi:10.1097/MD.0000000000046064Free full textPubMed 41305737DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error