A research study from McGill University, published in Science Advances, shows that this seasonal deficiency of Vitamin D can have substantial and long-lasting consequences, particularly for children. Risks of Vitamin D deficiency Vitamin D has a crucial role in the development and functioning of the immune system. The thymus is a gland that is affected by Vitamin D deficiency. The gland prepares and trains the immune cells to identify and fight any harmful invaders or pathogens in the body. Especially in children, the Vitamin D deficiency leads to premature ageing of this gland. This results in a 'leaky' immune system. This is a very serious condition that makes the immune cells mistakenly attack healthy tissues, leading to autoimmune diseases such as Type 1 diabetes. This study builds upon the findings of a 2001 study from Finland, which discovered that children who received vitamin D supplementation early in life had up to a five-fold reduced risk of developing Type 1 diabetes later. More about the research The lead researcher Professor John White and his team conducted elaborate experimentation on genetically modified rats with Vitamin D deficiency to understand better. Their examinations of the mice showed significant impacts on the thymus and immune systems of these mice. It established a link between Vitamin D and immunity. It has a high likelihood of mirroring in humans as well. Even though the experiment on done on mice, the similarities in thymus function across species indicate that the findings are relevant to human health as well. This further brings forth the role of Vitamin D in the bigger picture of human health. Earlier, researchers found the importance of Vitamin D in supporting bone health. But this study shows that it's important for immune regulation as well. The researchers found this promising as it might open up new doors for treating autoimmune diseases.