A 2026 systematic review of 13 studies found that while vitamins A, B1, B12, and D are commonly studied for dry eye disease, the evidence supporting their use remains weak and inconsistent. According to Gram Research analysis, no studies were judged to be high quality, most used different vitamin doses and had short follow-up periods, making it impossible to determine which vitamins actually work or what dose to take. Vitamin D was studied most frequently (61.5% of studies), followed by vitamin A (23%), but mixed results mean we cannot confidently recommend supplementation for dry eyes without more rigorous research.
Dry eyes affect millions of people, causing discomfort and blurred vision. According to Gram Research analysis of a systematic review published in 2026, scientists looked at 13 studies testing whether taking vitamin supplements by mouth could help dry eye disease. The research focused on vitamins A, B1, B12, and D. While some studies showed promise, the evidence isn’t strong enough yet to make firm recommendations. The main problem is that most studies were small, didn’t last very long, and used different vitamin doses, making it hard to know what really works.
Key Statistics
A 2026 systematic review of 13 studies published in Ophthalmic & Physiological Optics found that vitamin D was the most commonly studied supplement for dry eye disease, appearing in 61.5% of the research, yet none of the studies were judged to be high quality.
According to a 2026 systematic review analyzing 13 studies on oral vitamin supplementation for dry eye disease, vitamin A was examined in 23% of studies and a combination of vitamin B1 and mecobalamin in 15.5%, but no studies investigated vitamin C supplementation.
A 2026 systematic review of dry eye disease research found that most vitamin supplementation studies had significant limitations including small sample sizes, short follow-up periods lasting only weeks to months, and variable vitamin dosages, preventing researchers from drawing firm conclusions about efficacy.
The Quick Take
- What they studied: Whether taking vitamin supplements by mouth can reduce dry eye symptoms and improve eye surface health
- Who participated: 13 published research studies examining vitamin A, B1, B12, and D supplementation for dry eye disease
- Key finding: Most studies tested vitamin D (61.5% of studies) and vitamin A (23%), but none of the studies were considered high quality, and results were mixed
- What it means for you: While vitamins may help dry eyes, we don’t have strong enough evidence yet to say which vitamins work best or what dose to take. Talk to your eye doctor before starting supplements
The Research Details
Researchers searched five major medical databases (PubMed, Cochrane, Embase, Web of Science, and Scopus) for all studies published between April 2024 and January 2025 that tested oral vitamin supplements for dry eye disease. They followed strict guidelines called PRISMA to make sure they did the review properly and fairly. The researchers looked for studies that measured specific things like tear production, tear film stability, corneal damage, eyelid redness, and patient-reported eye discomfort.
Two independent reviewers checked each study to make sure it met the requirements and evaluated how well each study was done. They looked at 13 studies total that tested vitamins A, B1, B12, and D. The review focused on studies that measured objective eye tests (like the Schirmer test that measures tear production) and subjective measures (like patient pain ratings).
This type of systematic review is like a detective collecting all the clues from different investigations to see if they tell the same story. It’s considered one of the strongest types of research because it combines information from many studies rather than relying on just one.
Dry eye disease is increasingly common, especially with more screen time, and it can significantly affect quality of life. Understanding whether simple vitamin supplements could help is important because they’re accessible, affordable, and have few side effects compared to other treatments. A systematic review is the best way to answer this question because it looks at all available evidence rather than just one study, which helps avoid misleading conclusions.
The researchers found that none of the 13 studies they reviewed were judged to be high quality. This is an important limitation. Most studies had small numbers of participants, didn’t follow patients for very long (short follow-up periods), and used different vitamin doses, making it hard to compare results. The fact that no studies looked at vitamin C supplementation suggests the research in this area is still incomplete. When studies use different methods and doses, it’s harder to know if the vitamin itself works or if something else explains the results.
What the Results Show
The systematic review found that vitamin D was the most commonly studied supplement, appearing in 61.5% of the 13 studies reviewed. Vitamin A was studied in 23% of the research, while a combination of vitamin B1 and mecobalamin (a form of B12) was tested in 15.5% of studies. However, the results across these studies were inconsistent and mixed.
Because the studies varied so much in their design, participant numbers, vitamin doses, and how long they lasted, the researchers couldn’t combine the results into one overall conclusion. Some individual studies showed that certain vitamins improved tear production or reduced eye surface damage, but other studies found no benefit. The lack of high-quality studies means we can’t be confident about which vitamins actually work.
The researchers noted that the studies had significant weaknesses: many weren’t properly controlled (meaning they didn’t compare the vitamin group to a similar group taking a placebo), they didn’t have enough participants to detect real effects, and they often lasted only a few weeks or months when eye conditions may need longer to improve.
The review found that different studies measured dry eye disease in different ways, which made comparison difficult. Some focused on tear production (measured by the Schirmer test), others on tear film stability (break-up time), corneal damage (fluorescein staining), eyelid inflammation, or patient-reported symptoms using standardized questionnaires. This variation in measurement methods is another reason the results were hard to combine and interpret.
This 2026 systematic review represents the most comprehensive look at oral vitamin supplementation for dry eye disease to date. Previous research has suggested that vitamins play important roles in eye health and that vitamin deficiencies might be linked to dry eye disease, but this review found that the clinical evidence supporting supplementation is still weak. The review highlights a gap between what we know about vitamins’ theoretical benefits and what we’ve actually proven works in real patients.
The biggest limitation is that none of the 13 studies reviewed were considered high quality. Most studies had small sample sizes, meaning they didn’t include enough people to reliably detect whether the vitamins actually worked. The follow-up periods were very short—often just weeks or a few months—when dry eye disease may need longer to improve. Different studies used different vitamin doses, making it impossible to know what the right dose should be. Additionally, no studies examined vitamin C, leaving a gap in the evidence. The review was limited to English-language publications, so some research published in other languages may have been missed. Finally, the researchers couldn’t combine results statistically because the studies were too different from each other.
The Bottom Line
Based on current evidence, we cannot make strong recommendations about which vitamins to take for dry eyes or in what doses. The evidence is too limited and mixed. However, if you have dry eyes and a vitamin deficiency (which your doctor can test), correcting that deficiency may help. Vitamin D and vitamin A show the most research attention, but more high-quality studies are needed. Confidence level: LOW. Always consult your eye doctor before starting supplements, especially if you take other medications.
People with dry eye disease who are interested in natural approaches should care about this research. It’s particularly relevant for those who prefer supplements over prescription eye drops or other treatments. However, this research shouldn’t replace professional eye care. People with known vitamin deficiencies may benefit most from supplementation. Those with severe dry eye disease should work with their eye doctor on proven treatments rather than relying solely on supplements.
If vitamins do help dry eyes, improvements would likely take several weeks to months to notice, not days. Most dry eye conditions develop over time, so treatment also takes time. You should see your eye doctor regularly to monitor whether any treatment is working.
Frequently Asked Questions
Can taking vitamin D supplements help with dry eyes?
Vitamin D was studied most often for dry eyes (in 61.5% of reviewed studies), but results were mixed and inconsistent. A 2026 systematic review found no high-quality evidence proving vitamin D works, so more research is needed before recommending it as a treatment.
What’s the best vitamin supplement for dry eye disease?
Current research doesn’t identify a clear winner. Vitamins A, B1, B12, and D have been studied, but a 2026 systematic review found the evidence too weak to recommend any specific vitamin or dose. Talk to your eye doctor about your individual needs.
How long does it take for vitamin supplements to help dry eyes?
Most studies lasted only weeks to months, so we don’t know the realistic timeline. Eye conditions typically improve slowly, so if vitamins help, you’d likely need 8-12 weeks to notice changes. Consistent use and monitoring with your eye doctor is important.
Are vitamin supplements safe for treating dry eyes?
Vitamins are generally safe, but they’re not proven effective for dry eyes yet. A 2026 review found no high-quality studies supporting their use. Always tell your eye doctor about supplements you’re taking, as some can interact with medications or eye conditions.
Should I stop using eye drops and use vitamins instead?
No. A 2026 systematic review found insufficient evidence that vitamins alone treat dry eyes effectively. Continue using prescribed eye drops or treatments your doctor recommends. Vitamins might be a helpful addition, but discuss this with your eye care provider first.
Want to Apply This Research?
- Track daily vitamin supplementation (type, dose, time taken) alongside dry eye symptoms using a simple 1-10 discomfort scale, tear production observations, and screen time hours to identify patterns over 8-12 weeks
- Set daily reminders to take vitamin supplements at the same time each day, and log eye comfort scores before and after supplementation to monitor personal response
- Create a weekly summary view showing vitamin adherence percentage, average eye discomfort scores, and any correlations with screen time or environmental factors; share monthly reports with your eye care provider
This article summarizes a systematic review of existing research and is for informational purposes only. It does not constitute medical advice. Dry eye disease is a medical condition that requires professional diagnosis and treatment. Before starting any vitamin supplements, especially if you have dry eyes or take other medications, consult with your eye care provider or ophthalmologist. This review found that current evidence is limited and no studies were judged to be high quality. Individual results vary, and supplements should not replace proven medical treatments recommended by your healthcare provider. If you experience persistent dry eyes, vision changes, or eye pain, seek immediate professional medical attention.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.