Vitamin D3 and Your Eyes: Why So Many Adults Are Vitamin D Deficient

Vitamin D is often called the “bone vitamin,” but that’s only part of the story. Vitamin D3 (cholecalciferol) also influences systems your eyes rely on every day—especially as we get older: inflammation control, immune regulation, oxidative stress protection, and even how the body manages blood vessel growth.

And here’s the real-world issue: most people don’t get enough vitamin D consistently. Food sources are limited, sunlight is seasonal and complex (plus many of us avoid it for skin health), and modern indoor life takes care of the rest.

So instead of guessing, this article is about a more practical approach:

• Understand what vitamin D3 does
• See where the research is pointing for eye health
• Take the simplest action that actually helps—get your level checked

For seniors, particularly those over 70, the recommended daily intake of vitamin D is 800 IU (20 mcg) to maintain bone health and prevent deficiency, with some recommendations suggesting up to 1,000 IU daily. Up to 5,000 IU is often recommended to supplement daily, given that a large portion of the senior population is deficient in vitamin D.

A serum 25(OH)D level greater than 50 nmol/L (>20 ng/mL) is generally considered sufficient.

What is vitamin D3?

Vitamin D3 is the form your body can make when sunlight hits your skin. It’s then processed by the liver and kidneys into active forms that your tissues can use.

Most clinicians assess vitamin D status with a blood test called 25-hydroxyvitamin D, written as 25(OH)D. That number is your starting point.

Vitamin D is Being Studied Across Many Eye Conditions

Research has explored potential links between vitamin D3 levels and:

• Dry eye disease
• Glaucoma
• Myopia (nearsightedness)
• Keratoconus
• Thyroid eye disease
• Diabetic retinopathy / diabetic macular edema
• Age-related macular degeneration (AMD)
• Cataracts

Important: Vitamin D is not a stand-alone treatment for these conditions. Think of it as one foundational lever—especially if you’re deficient.

Dry Eye: When Low Vitamin D May Worsen Irritation + Inflammation

Dry eyes can look minor until you live with it: burning, redness, gritty sensation, watery eyes that still feel “dry,” and vision that fluctuates.

Studies have found that people with dry eyes often have lower vitamin D levels. ¹

Correcting vitamin D deficiency may support better tear stability, reduced inflammation, and improved symptoms when paired with standard dry-eye care. ²

If you’re doing the dry eye drops, the warm compresses, and taking regular screen breaks for active computer users, and it’s still not improving, visit your eye doctor. Also, ask your primary care physician for a vitamin D blood test. If you are low in vitamin D, take a vitamin D3 supplement.

Glaucoma: Not Just Pressure—Also Nutritional Support For Optic Nerve Health And Resilience

Glaucoma is one of the leading causes of irreversible vision loss. Eye pressure (IOP) is a major factor, but it’s not the whole story—glaucoma is also about protecting the optic nerve and retinal cells over time.

Research suggests vitamin D status may be associated with glaucoma risk. ³

Experimental research also points to vitamin D’s potential to support retinal cell survival and inflammatory balance. ⁴

Vitamin D won’t replace glaucoma drops or procedures. But if you’re at risk (family history, elevated IOP, age), it can be one of the essential nutrients to support optic nerve health.

AMD (Macular Degeneration) and Oxidative Stress

AMD affects the macula—the part of the retina responsible for sharp central vision. A consistent theme in AMD research is damage driven by oxidative stress and inflammation.

Studies have reported lower vitamin D levels in people with AMD compared to controls. ⁵

Vitamin D3 has been studied for protective effects in retinal cells, including reducing oxidative stress and supporting cell viability in retinal pigment epithelium models. ⁶

Some population research suggests vitamin D status may relate differently to early vs. late AMD, which is another reason testing vitamin D levels is recommended. ⁷

If AMD runs in your family, or you’re watching early changes, vitamin D is worth checking as part of a broader prevention plan. Also, avoid smoking, control your blood pressure, and take targeted eye nutrients.

Diabetic Retinopathy & Macular Edema: Inflammation + Blood Vessel Changes

In diabetes, eye damage is driven by chronic inflammation, oxidative stress, and changes in blood vessels in the retina. ⁸

Research has linked low vitamin D levels with higher risk of diabetic retinopathy in type 2 diabetes. ⁹

Vitamin D’s immune-modulating and anti-angiogenic (anti–abnormal blood vessel growth) properties are why it keeps showing up in this research area, including research on blood-retinal barrier integrity. ¹⁰

If you’re diabetic, vitamin D is one more “quiet” number to keep in range—right alongside A1C, blood pressure, and lipids.

Cataracts: A Possible Deficiency Pattern

Cataracts are extremely common with age. Several studies suggest people with cataracts are more likely to have low vitamin D levels. ¹¹

Vitamin D deficiency has also been linked to posterior subcapsular cataracts in some research. ¹²

One proposed mechanism involves vitamin D’s role in calcium regulation and lens cell function.

Cataracts are multi-factorial (UV exposure, age, smoking, diabetes, steroids). Vitamin D isn’t the only lever—but it’s one of the easier ones to measure and correct.

Myopia, Keratoconus, Thyroid Eye Disease

These areas are still evolving, but the pattern is consistent: vitamin D status may influence inflammation, immune signaling, and tissue remodeling.

Myopia: Some studies link lower vitamin D with myopia, but outdoor time and UV exposure may be confounding variables. ¹³

Keratoconus: Lower vitamin D levels have been reported more often in some groups, with interest in collagen/inflammation pathways. ¹⁴

Thyroid Eye Disease: Vitamin D deficiency appears more common in some thyroid eye disease populations. ¹⁵

These are not “vitamin D diseases.” But if you’re dealing with one of them, vitamin D is a sensible foundational check.

The Practical Bottom Line: Don’t Guess—Test

Ask your doctor to check your Vitamin D levels. Then:

• If you’re low, supplement based on your clinician’s guidance
• Re-test after a period of consistent supplementation
• Don’t rely on food alone (vitamin D is limited in most diets)
• Don’t assume sun exposure is enough (season, latitude, sunscreen use, skin tone, and time outdoors all change the outcome)

Quick Safety Note (Important)

Vitamin D is fat-soluble, so “megadosing” without laboratory tests and doctor supervision is not smart. Your goal is adequate, not extreme.

Suggested Supplements to Consider

Supportive options people commonly use (especially if labs show low D)

• Vitamin D3 (dose guided by your 25(OH)D test)
• Eye-aging nutrients often discussed in the research: lutein/zeaxanthin, omega-3s, antioxidant support
• Condition-specific support should be personalized (especially if you have diabetes, thyroid disease, or take blood thinners)

Not medical advice. Always check with your clinician, especially if you’re on prescriptions or managing a chronic condition.

Vitamin D3 5,000 + K

H2 Elite Molecular Hydrogen 60 tabs

Dr. Grossman’s Complete Eye Formula 2oz (oral spray)

Advanced Eye & Vision Support Formula (whole food) 60 vcaps

Dr. Grossman’s Advanced Eye and Dr. G’s Whole Food Superfood Multi1 20 Vcap Combo – 2 months supply

Dr. Grossman’s Blood Vessel Control Formula 2oz – helps reduce the risk of unwanted blood vessel growth, supports healthy circulation, reduces inflammation, and more.

Dr. Grossman’s Bilberry/Ginkgo Combination 2oz (60ml) – helps support healthy circulation, and strengthens blood vessels and capillaries.

Dr. Grossman’s Whole Food Organic Superfood Multi-Vitamin 120 Vcaps – whole food, organic, GMO free multivitamin.

NMN Wonderfeel Capsul 60 vegcaps – helps protect ganglion cells in the retina and optic nerves from damage, reduces inflammation, supports the immune system.

Related Home Device

Microcurrent Stimulation 100ile Purchase Option –  home unit for supporting retinal and optic nerve health. Summaries of 7 studies done to date are summarized on the product page.

Supplement Packages
AMD Package 4G

Corneal Support Package 2

Optic Nerve A-Support Package 1

Add H2 Elite to any of these packages as well.

Recommended Books

Natural Eye Care: Your Guide to Healthy Vision and Healing

Natural Brain Support: Your Guide to Preventing and Treating Alzheimer’s, Dementia, and Other Related Diseases Naturally

Natural Parkinson’s Support: Your Guide to Preventing and Managing Parkinson’s