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B Vitamins may decrease risk of age-related macular degeneration

February 10, 2009

A combination of vitamin B6, vitamin B9, and vitamin B12 may decrease the risk of age-related macular degeneration (AMD), the leading cause of severe irreversible vision loss in the elderly.

The randomized controlled trial, part of the Women’s Antioxidant and Folic Acid Cardiovascular Study (WAFACS), followed 5,442 female healthcare professionals aged 40 years or older, who already had or were at high risk of heart disease for a little more than seven years (1). Participants were assigned to receive a placebo or a combination of folic acid (2.5 mg/day), vitamin B6 (50 mg/day) and vitamin B12 (1 mg/day).

After two years, the beneficial effects on those women taking B vitamins emerged and persisted throughout the entire trial. After 7.3 years of follow-up, women taking the supplements had a 34% lower risk of any AMD and a 41% lower risk of visually significant AMD.

Previous observational studies have suggested an association between lower homocysteine concentrations in the blood and lower risk of age-related macular degeneration (AMD), while intervention studies have shown that vitamin B6, vitamin B9 (folic acid), and vitamin B12 may lower homocysteine levels. But no intervention study had yet examined the effect of B vitamin supplementation on AMD risk.

The researchers suggested that B vitamins could be combined with other supplemental nutrients including the antioxidants vitamins C and vitaminE and carotenoids beta-carotene and lutein, which have also been shown to lower the risk of AMD. These supplements in turn can be combined with other preventive measures, including avoiding smoking and excessive sun exposure to provide even further protection.

References

  1. Christen W. et al. Folic Acid, Pyridoxine, and Cyanocobalamin Combination Treatment and Age-Related Macular Degeneration in Women: The Women’s Antioxidant and Folic Acid Cardiovascular Study. Archives of Internal Medicine, 2009; 169(4):335–341.