How accurate is the supplement content in both generic and branded ophthalmology supplements?
Reviewed by Tasmin Berman

This prospective cross-section study compared the concentrations of Vitamin C, Vitamin E, Zinc, and Copper in five dietary supplements including both national and regional brands used for macular degeneration in the United States. They performed a comparative analysis using gas chromatography-mass spectrometry for Vitamin C, Vitamin E, Zinc and Copper content. Analysis using atomic absorption spectroscopy assessed whether the labelling of vitamin content was accurate. They found that the average percentage change for the vitamins compared to what was listed was 27.3% for Vitamin C, 3.7% for Vitamin E, 17.5% for Zinc and 17% for Copper. They compared the finding to the recommended daily dosage recommended in the AREDSII study and found four of the five products to have lower dosage than the recommendations. They found that both tablet and gel forms of supplements were relatively accurate compared to their product labelling. In some cases, the supplements contained higher than the manufacturers labelling but this was found to not be a level that would cause harm. The study suggests here there is no major difference between generic and branded products however they do not meet the recommended doses from the AREDSII study, and this should be considered when recommending such products especially in those patients with higher risk factors for age-related macular degeneration. – TB

Vitamin analysis comparison study.
Fleissig E, Apenbrinck E, Zhang X, et al.
AMERICAN JOURNAL OF OPHTHALMOLOGY
August 2020 [Epub ahead of print].