Zeaxanthin

Lutein and zeaxanthin are both xanthophyll carotenoids that form the macular pigment, but they have distinct spatial distributions across the macula that reflect different protective roles. Zeaxanthin concentrates most densely in the fovea centralis — the central 0.5mm of the macula containing the highest density of cone photoreceptors responsible for sharp central vision, reading, and colour discrimination. Lutein predominates in the parafoveal and peripheral macular ring surrounding the fovea. A third macular carotenoid, meso-zeaxanthin (a metabolic conversion product of lutein), is found at the very centre of the fovea. Together, the three carotenoids form a spatial gradient of macular pigment, with each protecting the retinal region where it preferentially accumulates. For supplement formulators, this means lutein + zeaxanthin together provide more complete macular protection than either alone, and the AREDS2 5:1 ratio (10mg lutein : 2mg zeaxanthin) reflects approximate dietary intake patterns and macular tissue ratios.

The AREDS2 trial used zeaxanthin at 2mg per day, always in combination with lutein at 10mg per day (a 5:1 ratio). This combination replaced beta-carotene from the original AREDS formula and demonstrated a 25% reduction in the risk of progression to advanced AMD in participants with intermediate AMD or advanced AMD in one eye. The 2mg zeaxanthin dose is the clinical reference standard. Some premium eye health products use higher zeaxanthin doses (4–8mg) alongside 10–20mg lutein to increase the zeaxanthin:lutein ratio closer to the foveal tissue ratio, but the AREDS2 2mg dose remains the primary benchmark. For labelling purposes, citing AREDS2 requires matching the specific dose and combination used in the trial.

Meso-zeaxanthin is a stereoisomer of zeaxanthin — same molecular formula (C₄₀H₅₆O₂), same molecular weight, but a different arrangement of atoms around the 3'-hydroxyl group (R configuration in zeaxanthin vs S configuration in meso-zeaxanthin). In the eye, meso-zeaxanthin concentrates at the very centre of the fovea (the umbo) and is thought to be metabolically converted from lutein in retinal tissue — it is found only in very small amounts in dietary sources. Supplements providing all three macular carotenoids (lutein + zeaxanthin + meso-zeaxanthin) theoretically address the complete macular pigment spectrum. Meso-zeaxanthin is available as a synthetic ingredient and is used in some premium products marketed as "complete macular pigment" supplements. SV Botanica can supply meso-zeaxanthin on request in addition to natural zeaxanthin.

Yes — SV Botanica can supply a pre-blended lutein + zeaxanthin concentrate at the AREDS2 5:1 ratio (lutein 20% + zeaxanthin 4% in marigold oleoresin), standardised and batch-tested by HPLC for both carotenoid contents. This simplifies manufacturing for supplement brands targeting the AREDS2 reference formulation, as they receive a single ingredient with both carotenoids confirmed at the correct ratio in a single oleoresin matrix, rather than managing two separate carotenoid ingredients and blending at manufacturing. The pre-blend is supplied in nitrogen-flushed, refrigerated containers and comes with a combined COA specifying lutein content, zeaxanthin content, and the lutein:zeaxanthin ratio. Custom ratios are also available on request.

Zeaxanthin, like all carotenoids, is sensitive to light, oxygen, and heat. Oleoresin grades should be stored at 2–8°C in nitrogen-flushed, opaque containers and have a shelf life of 18 months under these conditions. Crystalline high-purity zeaxanthin has slightly better stability and can be stored at below 25°C with a 24-month shelf life if nitrogen-flushed and light-protected. Once opened, oleoresin containers should be used promptly or re-sealed under nitrogen. For finished supplement products, softgel formats with antioxidant co-ingredients (vitamin E, rosemary extract) provide the best finished-product stability. Avoid storing carotenoid ingredients in clear or translucent containers even under refrigeration, as UV from fluorescent lighting degrades carotenoid potency over time.