Vitamin B Intake Is Associated With Lower Incidence of Open-Angle Glaucoma: The Rotterdam Study

There is increasing evidence that B-vitamins may be important for open-angle glaucoma (OAG) prevention due to their roles in neuroprotection, vascular health, and the regulation of homocysteine metabolism, which may influence optic nerve integrity and intraocular pressure (IOP). Therefore, we examined the association between dietary intake of B-vitamins and incident OAG (iOAG).

We used data from the Rotterdam Study, a prospective, population-based cohort study in the Netherlands.

We included participants who were free of OAG at baseline, had at least 1 ophthalmic follow-up, and complete data on dietary intake. Among 6742 participants (mean [standard deviation]; age, 62.4 [7.4] years; 58.2% female), 162 developed iOAG.

The associations between energy-adjusted dietary intake of B-vitamins and iOAG, IOP, retinal nerve fiber layer (RNFL) thickness, and ganglion cell layer (GCL) thickness were assessed using multivariable logistic and linear regression analyses, respectively. All analyses were adjusted for at least age, sex, caloric intake, diet quality, and follow-up time.

The primary outcome was iOAG. Secondary outcomes included IOP, RNFL thickness, and GCL thickness.

Dietary intakes of niacin (vitamin B3; odds ratio [OR] with corresponding 95% confidence interval [CI]: 0.94 [0.90-0.98] per mg/d) and cobalamin (vitamin B12; OR [95%CI]: 0.90 [0.83-0.97] per µg/d) were significantly associated with decreased iOAG. Participants with the highest niacin intake (Q5, mean crude intake: 23.27 mg/d) had a significantly lower risk of iOAG (OR [95%CI]: 0.43 [0.21-0.86], p-trend=0.02) compared to those with the lowest intake (Q1, mean crude intake: 9.98 mg/d). A similar association was observed for cobalamin (Q5 [mean crude intake: 10.47 µg/d] vs. Q1 [mean crude intake: 0.19 µg/d], OR [95%CI]: 0.25 [0.12-0.52], p-trend<0.001). Moreover, there was a significant trend towards a lower IOP with higher niacin (p-trend=0.04) and cobalamin (p-trend=0.03) intake. Additionally, cobalamin intake was associated with increased GCL thickness (Beta [95%CI]: 0.01 [0.00-0.03] µg/d; p-trend=0.002). Other B-vitamins were not associated with iOAG or the OAG-associated outcomes.

Higher dietary intake of niacin and cobalamin was associated with a lower risk of iOAG. Niacin supplementation may be recommended to individuals with a high genetic susceptibility for OAG. More research on cobalamin is warranted.