While the answer to this question does involve some level of complexity and nuance, the short answer is no—not all vitamins for Age-Related Macular Degeneration (AMD) are the same. While manufacturers formulate their supplements based on the available scientific evidence, the interpretation of that evidence is where the formulations can vary significantly in terms of dosages and exact nutrients. Given that patients may potentially be taking the same supplement for many years, it is important to gain guidance from your eye doctor as to which supplement is best for each individual patient suffering from AMD.
Vitamins for macular degeneration are primarily based on the biggest and most well-known studies—the Age-Related Eye Disease Study (AREDS) and its follow-up, AREDS2, published in 2001 and 2013, respectively. These studies investigated the effects of predetermined combinations of nutrients on the progression of AMD in thousands of well-nourished patients over several years. The primary goal was to see how many patients progressed from the “intermediate” stage of the disease to the “advanced” stage when taking a supplement versus a placebo.
“AREDS” vitamin formulas generally contain:
- Antioxidant Vitamins: Vitamins C (500 mg daily) and E (400 IU daily) as they have been found to help protect retinal cells from oxidative damage.
- Carotenoid Antioxidants: Beta-carotene (15 mg daily in the original AREDS formula) has been widely substituted for lutein and zeaxanthin (10 mg and 2 mg, respectively) based on findings from AREDS2 showing a further reduction in risk of progression and improved safety with these xanthophyll carotenoids compared to beta-carotene.
- Zinc: This trace mineral is essential for eye health and plays a role in maintaining the structure and function of the retina. However, high doses of zinc can interfere with the absorption of other important minerals, like copper, and can cause side effects (such as nausea, headaches, and gastrointestinal issues). The optimal dose has been a subject of debate. Many formulas contain 80 mg of zinc daily, which was the dose in the original AREDS study. However, in AREDS2, 80 mg was shown to be no more effective than 25 mg of zinc daily for risk of AMD progression. Since 80 mg of zinc is double the maximum safe dose and approximately 8–10 times the recommended daily allowance of zinc for the general population, I strongly recommend 25 mg as opposed to 80 mg for patients who are recommended to take zinc.
- Copper (1.2–2 mg daily): Added to prevent copper deficiency that can result from high zinc intake.
Therefore, for patients who have been diagnosed with intermediate-stage AMD, it is recommended that they take a supplement modeled after the formulas shown to be beneficial in the AREDS trials. At Inspired Eyes Optometry, I recommend my patients take a supplement with a maximum of 25 mg of zinc as opposed to 80 mg of zinc. Additionally, there may be a benefit for other supportive nutrients (e.g., B vitamins, omega-3s, meso-zeaxanthin) and genetic testing to optimize this individualized recommendation further. As always, we recommend consulting with your eye doctor for guidance on your specific situation.
Dr. Daniel Walker, OD, FOWNS, FCOVD
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