Exposing yourself to the sun for short periods, following a varied and balanced diet that includes foods such as salmon, sardines, mushrooms and eggs, and, in some cases, also resorting to specific supplements, the important thing is to ensure a constant supply of vitamin D. Vitamin D, in fact, supports the immune system, protects the heart and counteracts cellular degeneration. And from today we know that it helps to preserve eye health, by reducing the risk of dry eye, glaucoma, progression of myopia but also eye inflammation such as uveitis. This emerges from a very recent review that appeared in the International Journal of Molecular Science (Chan et al, Int J Mol Sci, 2022).
Vitamin D, the vitamin of health
Vitamin D is considered the vitamin of long life, and it really is. When vitamin D is not lacking in the body, it helps to strengthen the immune defences, counteracts inflammation and cellular degeneration, promoting apoptosis, which is the programmed death of diseased cells, and inhibiting angiogenesis, which is the formation of new blood vessels that would bring nourishment to the tumor. Instead, low levels of vitamin D are associated with an increased risk of developing cardiovascular disease, hypertension, cancer and diabetes. Several studies have also focused on the ability of vitamin D to protect vision. The review we are talking about today collected, compared and analyzed the results of 162 searches. Here's what emerged.
Vitamin D and eye health
Dry eye syndrome is a condition that affects up to 12% of the world's population. Dry eye is accompanied by ocular inflammation and vision disturbances. Studies have shown that vitamin D protects against dry eye syndrome. But the action of vitamin D on dry eye is not only preventive. There is strong evidence, in fact, that taking vitamin D through supplements can even improve dry eye syndrome if it is already present. Vitamin D also reduces the risk of diabetic retinopathy, a complication of diabetes 1 and 2 affecting the blood vessels in the retina. Vitamin D also confers protection from glaucoma, a condition that, if left untreated, can lead to the death of cells in the retinal ganglia and loss of vision. Not only that, vitamin D has also shown moderate protection against macular degeneration. It is believed that this is due to the ability of vitamin D to inhibit angiogenesis, i.e. in this case the formation of new blood vessels in the macula. Then, the amount of vitamin D present is inversely proportional to the progression of myopia even if in this case the link is not yet clear. Finally, vitamin D, thanks to its anti-inflammatory action, also seems to protect the eye from inflammation such as uveitis. In fact, low levels of vitamin D are associated with a higher risk of developing uveitis. Not only that, taking vitamin D during active uveitis has been shown to reduce its symptoms and to improve its course.
We have seen many good reasons to ensure an adequate supply of vitamin D. In addition to the health of the immune system, the heart and the entire body, vision also benefits from the presence of this vitamin. According to studies, to obtain the right amount of vitamin D, 5 to 30 minutes of sun exposure of the face, arms, legs or back without protection is sufficient, always keeping the eyelids closed and avoiding the central hours of the day to protect the eyes and skin from UV damage. Vitamin D is also taken with the diet. Hence the importance of not missing foods such as certain types of fish, such as trout, salmon and sardines, mushrooms, eggs, fortified milk and dairy products and, to a lesser extent, even dark chocolate. Alternatively, after talking to your doctor, you can also resort to vitamin D supplements.