Eyes need to maintain their moisture. That’s why they make tears. If they don’t make enough tears, or if the tears are of poor quality, the eyes become dry. They may feel as though they have grit in them, even when there is none. They may water excessively, and vision might be blurry. The whole experience of dry eyes is very uncomfortable. Although there are a number of treatments (we have written about them here, here and here), one reader found the key to overcoming dry eyes was more vitamin D.
A Dry Eye Saga:
Q. For over a year, I suffered from severely dry, red eyes. This not only limited my reading but also looked so unpleasant I was embarrassed. I tried various types of eye drops my ophthalmologist recommended but they offered little to no relief.
At my last physical, my GP noted that my vitamin D level was extremely low and prescribed 5000 IUs per day. Within a couple weeks, my eyes were back to normal. All the redness and discomfort was gone. Have you heard of others using vitamin D supplements for dry eyes?
Do Dry Eyes Need More Vitamin D?
A. Your question sent us to the medical literature. We found conflicting reports on the value of vitamin D supplements. In a Korean study, higher blood levels of vitamin D were associated with a lower likelihood of symptoms, but it was not statistically significant (Jeon et al, Journal of Preventive Medicine and Public Health, Nov. 2017).
Australian investigators, on the other hand, have found that low vitamin D levels are associated with dry eye symptoms (Yang et al, Contact Lens & Anterior Eye, Feb. 2018). They found that people taking vitamin D supplements had fewer dry-eye symptoms and better tear quality. Another study found that a single injected very-high-dose supplement measurably improved symptoms in people who had not responded to other treatments (Bae et al, Scientific Reports, Oct. 4, 2016).
Turkish scientists also found that giving people with vitamin D deficiency more vitamin D as a supplement improved tear quality (Kizilgul et al, Seminars in Ophthalmology, online Sep. 6, 2017). Tear quality is closely correlated with dry eye symptoms (Schargus et al, Cornea, July 2015).
Learn More:
If you would like to learn more about this crucial vitamin, you might want to read our Guide to Vitamin D Deficiency. To learn more about dry eyes, you could listen to Dr. Peter McDonnell, director of the Johns Hopkins Wilmer Eye Institute.
