A prospective study of folate, vitamin B₆, and vitamin B₁₂ intake in relation to exfoliation glaucoma or suspected exfoliation glaucoma.
OBJECTIVE
Effective strategies for primary prevention are lacking for exfoliation glaucoma (EG), which is the most common type of secondary glaucoma.


OBJECTIVE
To examine the association between B vitamin intake and EG or suspected EG (EG/SEG) risk.


METHODS
National prospective cohort study using more than 20 years of follow-up data from the Nurses' Health Study (all female registered nurses) and the Health Professionals Follow-up Study (all male health professionals) from June 1, 1980, to May 31, 2010 (Nurses' Health Study) and January 1, 1986, to December 31, 2010 (Health Professionals Follow-up Study). We included a subset of 78,980 Nurses' Health Study women and 41,221 Health Professionals Follow-up Study men who were 40 years or older, free of glaucoma, had completed diet questionnaires, and reported eye examinations (follow-up rate, >85%).


METHODS
Cumulatively updated intake of B vitamins (folate, vitamin B6, and vitamin B12) as ascertained by repeated administration of validated questionnaires.


METHODS
Incident cases of EG/SEG, totaling 399 (329 women and 70 men), were first identified with the questionnaires and were subsequently confirmed with medical records. Multivariable relative risks for EG/SEG were calculated in each cohort and then pooled with meta-analysis.


RESULTS
Vitamin B₆ and vitamin B₁₂ intake was not associated with EG/SEG risk in pooled analyses (P = .52 and P = .99 for linear trend, respectively). However, a suggestive trend of a reduced risk was observed with higher intake of folate: compared with the lowest quintile of cumulatively averaged updated total folate intake, the multivariable relative risk for EG/SEG for the highest quintile (≥654 μg/d) was 0.75 (95% CI, 0.54-1.04; P = .02 for linear trend). These results were not materially altered after adjustment for vitamin B₆ and vitamin B₁₂ intake. An association was observed for supplemental folate intake but not for dietary folate only (P = .03 and P = .64 for linear trend, respectively). Greater frequency of multivitamin use showed a modest suggestive inverse association (current multivitamin use of ≥6 times per week vs nonuse multivariable relative risk, 0.84; 95% CI, 0.64-1.11; P = .06 for linear trend).


CONCLUSIONS
Higher total folate intake was associated with a suggestive lower risk for EG/SEG, supporting a possible causal role of homocysteine in EG/SEG.
Channing Division of Network Medicine, Department of Medicine, Brigham & Women's Hospital, and Harvard Medical School, Boston, Massachusetts.
Jae H
JH
Kang
Glaucoma Service, Massachusetts Eye and Ear, Boston, Massachusetts.
Stephanie J
SJ
Loomis
Glaucoma Service, Massachusetts Eye and Ear, Boston, Massachusetts.
Janey L
JL
Wiggs
Channing Division of Network Medicine, Department of Medicine, Brigham & Women's Hospital, and Harvard Medical School, Boston, Massachusetts3Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts4Department of Epidemiology, Harvar.
Walter C
WC
Willett
Channing Division of Network Medicine, Department of Medicine, Brigham & Women's Hospital, and Harvard Medical School, Boston, Massachusetts2Glaucoma Service, Massachusetts Eye and Ear, Boston, Massachusetts.
Louis R
LR
Pasquale
D000328:Adult; D019587:Dietary Supplements; D017889:Exfoliation Syndrome / Q000188:drug therapy* / Q000503:physiopathology; D005260:Female; D005492:Folic Acid / Q000627:therapeutic use*; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome; D014805:Vitamin B 12 / Q000627:therapeutic use*; D025101:Vitamin B 6 / Q000627:therapeutic use*; D014803:Vitamin B Complex / Q000627:therapeutic use
D014803:Vitamin B Complex; D025101:Vitamin B 6; D005492:Folic Acid; D014805:Vitamin B 12