Eye diseases are linked to vitamin and mineral deficiencies and overweight

Vitamins and minerals are crucial for eye health and vision because they are involved in numerous metabolic processes and act as powerful antioxidants that protect the vulnerable eyes and optic nerve from damage caused by free radicals and oxidative stress. Evidence suggests that deficiencies in vitamins A, B, C, and D, as well as minerals such as magnesium, selenium, zinc, and copper increase the risk of dry eyes, cataracts, AMD, optic nerve damage, and other eye diseases. In addition, being overweight can be an additional risk factor for AMD, diabetic retinopathy, and glaucoma, according to a review published in Nutrients. The authors emphasize that early detection of deficiencies and targeted supplementation can prevent or slow the progression of many eye diseases.

The eyes are among the most metabolically active organs in the body, with blood flow comparable to that of the brain and heart. This makes the eyes particularly vulnerable if cells lack the vitamins and minerals needed for their many functions. Moreover, the high blood flow and oxygen supply make the eyes especially susceptible to oxidative stress, a condition in which there are too many free radicals relative to protective antioxidants. Excess free radicals can attack and destroy eye tissue. The retina, which consists of specialized nerve cells and photoreceptors (visual cells), has a particularly high demand for a continuous supply of vitamins and minerals to maintain its normal functions and protect against oxidative stress. This also includes protection against chronic inflammation, often present in overweight individuals and in many chronic diseases, including type 2 diabetes.
The purpose of the new review study was to examine the relationship between deficiencies in various vitamins and minerals, overweight, and eye diseases. Using relevant search terms, the researchers collected 50 relevant studies from the past 10 years from databases such as PubMed and ScienceDirect. The study found that deficiencies in vitamins A, D, E, C, and various B vitamins were consistently associated with:

• Local inflammation on the eye’s surface
• Local oxidative stress
• Cataracts
• AMD (Age-related Macular Degeneration)
• Inflammation of the optic nerve

Deficiencies in magnesium, selenium, zinc, and copper further increase the risk of:

• Impaired function of retinal photoreceptors
• Glaucoma
• Retinal degeneration

Overweight, and particularly type 2 diabetes, is associated with oxidative stress and circulatory dysfunction, which itself can increase the risk of:

• AMD
• Diabetic retinopathy

In addition, previous studies (AREDS/AREDS2) show that high-dose antioxidant supplementation can slow the progression of AMD.
The researchers conclude that adequate intake of various vitamins and minerals plays a crucial role in multiple metabolic processes that are essential for overall eye health. Early detection of deficiencies and targeted supplementation can prevent or delay the onset of various eye diseases.
In the review published in Nutrients, the authors also outline the specific roles of vitamins and minerals in eye health:

Vitamin A

Vitamin A (retinol) is found in animal sources such as liver, butter, egg yolk, cheese, and fatty fish. Retinol is the active form of vitamin A, which is essential for the formation of rhodopsin, the pigment that allows us to see in low light.
Plant sources, such as carrots, cabbage, tomatoes, and bell peppers, contain beta-carotene, a potent antioxidant that protects the eyes from oxidative stress and serves as a precursor to retinol. Subclinical vitamin A deficiency can cause dry eyes and night blindness. Worldwide, severe vitamin A deficiency is a leading cause of childhood blindness.

Vitamin D
Most cells in the body have vitamin D receptors, including cells in the cornea, conjunctiva (the white of the eye), retina, and tear glands. Vitamin D regulates gene activity affecting the immune system and the control of local inflammation and oxidative stress.
Vitamin D deficiency increases the risk of dry eye disease (DED), especially in postmenopausal women and those with autoimmune disorders. A vitamin D deficiency also increases the risk of subcapsular cataracts, diabetic retinopathy, and AMD.

Vitamin E

Vitamin E primarily functions as a powerful antioxidant, which is especially important for eye health because photoreceptors contain polyunsaturated fatty acids that are highly vulnerable to free radical damage and oxidative stress.
Vitamin E deficiency can lead to retinal dysfunction and degeneration, and photoreceptor apoptosis (programmed cell death). Several studies have shown that vitamin E supplementation can slow the progression of AMD.

B vitamins

B vitamins are critical for cellular energy metabolism, maintenance of optic nerve function, and local circulation.
B6, folate, and B12 are essential for breaking down homocysteine, which in elevated levels can damage circulation and cause local inflammation.
Because the eye has high energy demands, even minor B vitamin deficiencies can negatively affect eye health.
Alcoholism can deplete B1 (thiamine), and severe deficiency can cause Wernicke-Korsakoff syndrome, a serious brain disorder also affecting the eyes, requiring immediate high-dose B1 supplementation.

Vitamin C

Vitamin C is important for collagen synthesis, connective tissue, immune function, wound healing, and acts as a potent antioxidant. In the eye, vitamin C helps maintain the structural integrity of the sclera, cornea, conjunctiva, and other tissues. Partial deficiency (subclinical scurvy) can lead to fragile blood vessels, hemorrhages, and impaired healing. Severe deficiency (scurvy) can cause internal bleeding, including in the eye, and can be life-threatening.
As an antioxidant, vitamin C supplementation can help slow cataract development in diabetic patients.

Magnesium

Magnesium is involved in roughly 300 enzymatic processes, including nervous system function, blood sugar regulation, muscle function, vitamin D activation, and inflammation control. Numerous studies show that magnesium deficiency increases the risk of diabetes, diabetic retinopathy, and cataracts. Some pilot studies indicate that magnesium supplementation can help regulate intraocular pressure in early glaucoma.

Selenium

Selenium is part of 25–30 selenoproteins, including powerful antioxidants (GPXs) that protect retinal cells and other cells from oxidative stress. Selenium works closely with vitamin E as an antioxidant. Selenium deficiency increases the risk of impaired repair of oxidative damage, retinal degeneration, and cataracts.

Zinc and copper

Zinc is involved in hundreds of enzymatic processes and functions as a potent antioxidant called superoxide dismutase (SOD). Zinc is especially important for wound healing, retinal health, and stabilization of cell membranes. Zinc deficiency can contribute to increased oxidative stress, impaired local healing, night blindness, and AMD. High-dose zinc supplementation combined with other antioxidants can slow AMD progression.
Copper is important for energy metabolism, antioxidant activity (part of SOD), and iron metabolism. Regarding eye health, copper is critical for optic nerve function. Copper deficiency can contribute to progressive optic nerve inflammation, resembling clinical B12 deficiency. A proper balance between zinc and copper is essential, as long-term high-dose zinc supplementation can lead to copper deficiency, while excessive copper, particularly from environmental toxins, can cause zinc deficiency.

References:

Corina Georginana et al. Associations Between Nutritional Factors, Obesity and Ocular Diseases: A Narrative Literature Review. Nutrients 2025

Tianarnan D.L. et al. Oral Antioxidant and Lutein/Zeaxanthin Supplements Slow Geographic Atrophy Progression to the Fovea in Age-Related Macular Degeneration. Ophthalmology, 2024

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