Vitamin D rejuvenates aging eyes by reducing inflammation, clearing amyloid beta and improving visual function

Vitamin D3 plays a key role in immune regulation and may protect against the aging process. A focal point for age-related changes is the outer retina of the eye where there is high metabolic demand resulting in a gradual increase in extracellular deposition, inflammation, and cell loss giving rise to visual decline. Here, we demonstrate that vitamin D3 administration for only 6 weeks in aged mice significantly impacts on this aging process. Treated mice showed significant reductions in retinal inflammation and levels of amyloid beta (Aβ) accumulation, which is a hallmark of aging. They also had significant reductions in retinal macrophage numbers and marked shifts in their morphology. These changes were reflected in a significant improvement in visual function, revealing that vitamin D3 is a route to avoiding the pace of age-related visual decline. Excess amyloid beta deposition and inflammation are risk factors leading to age-related macular degeneration (AMD), the largest cause of blindness in those older than 50 years in developed countries. Recently, vitamin D3 has been linked epidemiologically to protection against age-related macular degeneration. Hence, vitamin D3 enrichment is likely to represent a beneficial route for those at risk.