According to a Swedish study, people who were born in winter or in places where days are shorter and have less sunlight may have a lower risk of celiac disease compared to people born in warmer regions or seasons.
Celiac disease is an autoimmune disorder that damages and interferes with the absorption of nutrients from food. People with this condition cannot tolerate gluten, a protein in wheat, rye, and barley.
Scientists still don’t know the exact causes of the disease, but some previous studies pointed out the potential for the season of birth of a baby to be among many environmental factors able to affect the risk according to the lead author of the research Fredinah Namatovu, a public health researcher at the Umea University in Sweden.
Namatovu says: “Seasons of birth and area of birth appears to play a role. Season and region of birth could be a proxy for other factors such as vitamin D and viral infections.”
More detail here.