TL;DR

Several studies have found that people with dry eye are more likely to have low vitamin D levels. Since the test is inexpensive and vitamin D deficiency is common, it may be worth asking your healthcare provider to check your level.

Why Vitamin D for Dry Eyes?

  • regulates inflammation
  • immune function
  • tear stability
  • ocular surface

What Do the Studies Show About Vitamin D and Dry Eyes

Vitamin D helps regulate inflammation and immune function, while studies suggest deficiencies of both vitamins may contribute to dry eye in some people. Vitamin D has been extensively studied [1-8].

Why Test Instead of Guess?

A vitamin D blood test typically costs around $40–50 (often covered by insurance when appropriate). If your level is low, correcting the deficiency may improve far more than your eyes. Vitamin D has also been linked to bone health, immune function, muscle strength, and many other aspects of health.

Bottom Line

Dry eyes have many possible causes, but vitamin D deficiency is common, inexpensive to test for, and supported by a growing body of research. If you struggle with dry eyes, asking your healthcare provider to check your vitamin D level may be a simple first step.

Want to learn more about other possible causes? [Click here to read more about dry eyes.]

Selected References:

  1. Yoon, S.Y.; Bae, S.H.; Shin, Y.J.; Park, S.G.; Hwang, S.H.; Hyon, J.Y.; Wee, W.R. Low Serum 25-Hydroxyvitamin D Levels Are Associated with Dry Eye Syndrome. PLoS ONE 2016, 11, e0147847.
  2. Yildirim, P.; Garip, Y.; Karci, A.A.; Guler, T. Dry eye in vitamin D deficiency: More than an incidental association. Int. J. Rheum. Dis. 2016, 19, 49–54.
  3. Kuo, C.Y.; Huang, Y.C.; Lin, K.J.; Tsai, T.Y. Vitamin D Deficiency Is Associated with Severity of Dry Eye Symptoms and Primary Sjögren’s Syndrome: A Systematic Review and Meta-Analysis. J. Nutr. Sci. Vitaminol. 2020, 66, 386–388.
  4. Meng, Y.F.; Lu, J.; Xing, Q.; Tao, J.J.; Xiao, P. Lower Serum Vitamin D Level Was Associated with Risk of Dry Eye Syndrome. Med. Sci. Monit. Int. Med. J. Exp. Clin. Res. 2017, 23, 2211–2216.
  5. Shetty, R.; Sethu, S.; Chevour, P.; Deshpande, K.; Pahuja, N.; Nagaraja, H.; Pindipapanahalli, N.; Ghosh, A. Lower Vitamin D Level and Distinct Tear Cytokine Profile Were Observed in Patients with Mild Dry Eye Signs but Exaggerated Symptoms. Transl. Vis. Sci. Technol. 2016, 5, 16.
  6. Askari, G.; Rafie, N.; Miraghajani, M.; Heidari, Z.; Arab, A. Association between vitamin D and dry eye disease: A systematic review and meta-analysis of observational studies. Contact Lens Anterior Eye J. Br. Contact Lens Assoc. 2020, 43, 418–425.
  7. Kurtul, B.E.; Özer, P.A.; Aydinli, M.S. The association of vitamin D deficiency with tear break-up time and Schirmer testing in non-Sjögren dry eye. Eye 2015, 29, 1081–1084.
  8. Lee, J.H.; Kim, S.J.; Byun, Y.S.; Lee, J.; Park, S.H.; Chung, S.H. The Association of Serum Vitamin D Level With the Severity of Dry Eye Parameters in Primary Sjögren Syndrome. Cornea 2020, 39, 702–705.