Association of vitamin C with the risk of age-related cataract: a meta-analysis.
OBJECTIVE
Whether vitamin C is a protective factor for age-related cataract remains unclear. Thus, we conducted a meta-analysis to summarize the evidence from epidemiological studies of vitamin C and the risk of age-related cataract.


METHODS
Pertinent studies were identified by searching in PubMed and in Webscience. The random effect model was used to combine the results. Meta-regression and subgroups analyses were used to explore potential sources of between-study heterogeneity. Publication bias was estimated using Egger's regression asymmetry test.


RESULTS
Finally, 15 articles with 20 studies for vitamin C intake and eight articles with 10 studies for serum ascorbate were included in this meta-analysis. The relative risk (RR) and 95% confidence interval of cataract for the highest versus the lowest category of vitamin C intake was 0.814 (0.707-0.938), and the associations were significant in America and Asia. Significant association of cataract risk with highest versus the lowest category of serum ascorbate was found in general [0.704 (0.564-0.879)]. Inverse associations were also found between serum ascorbate and nuclear cataract and posterior subcapsular cataract.


CONCLUSIONS
Higher vitamin C intake and serum ascorbate might be inversely associated with risk of cataract. Vitamin C intake should be advocated for the primary prevention of cataract.
Department of Ophthalmology, The Second Artillery General Hospital, Beijing, China.
Lin
L
Wei
Department of Ophthalmology, The Second Artillery General Hospital, Beijing, China.
Ge
G
Liang
Department of Ophthalmology, The Second Artillery General Hospital, Beijing, China.
Chunmei
C
Cai
Department of Ophthalmology, The Second Artillery General Hospital, Beijing, China.
Jin
J
Lv
D000375:Aging; D000975:Antioxidants / Q000008:administration & dosage*; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000097:blood; D002386:Cataract / Q000453:epidemiology*; D004032:Diet; D019587:Dietary Supplements; D006801:Humans; D012307:Risk Factors; D014815:Vitamins / Q000097:blood*
D000975:Antioxidants; D014815:Vitamins; D001205:Ascorbic Acid
age-related cataract; meta-analysis; serum ascorbate; vitamin C