Dry Eye and Vitamin D
A very large study of over 10 million patients found that people with low vitamin D levels were about 30% more likely to have dry eye disease and other tear-related problems. Vitamin D plays an important role in the immune system and eye surface health, which may explain this connection. The researchers suggest that checking for and treating vitamin D deficiency could help manage or possibly prevent dry eye. More studies are needed to see whether vitamin D supplements can improve dry eye symptoms.