Potential side effects of AREDS vitamins and minerals include diarrhea, dizziness, headache and stomach upset, reports Drugs.com. Severe side effects include allergic reactions causing hives, difficulty breathing and swelling of the face and mouth; persistent diarrhea, nausea or vomiting; stomach pain; and yellowing of the skin or eyes.
The Age-Related Eye Disease Study, released in October 2001, was conducted by the National Eye Institute to study the progression of age-related macular degeneration and cataracts and to evaluate the effectiveness of selected vitamins and minerals in treating these conditions, according to the National Eye Institute. The results of the study indicated that high doses of vitamins C and E, beta-carotene, and zinc significantly reduced the development of vision loss due to macular degeneration, but they had no effect on cataracts.
The second AREDS report, completed in May 2013, added omega-3 fatty acids, lutein and zeaxanthin to the selection of vitamins and minerals evaluated. It also substituted lutein and zeaxanthin for the beta-carotene, which had been linked to an increased risk of lung cancer in smokers, reports the NEI. This test found that lutein and zeaxanthin were both safer and equally effective as beta-carotene, but omega-3 fatty acids had no impact on the experimental formulation of vitamins and minerals.