McGill Study Links Childhood Vitamin D Deficiency to Higher Autoimmune Disease Risk

A McGill University study explains why vitamin D shortage early in infancy is linked to a higher risk of autoimmune illnesses as Canadians prepare for "vitamin D winter," which is defined as months when the sun's angle is too low for the skin to synthesize the vitamin. The thymus aids in teaching immune cells in childhood to discriminate between dangerous invaders and the body's own tissues. The researchers found that the thymus ages more rapidly when there is a vitamin D shortage at that period of life. The primary author, John White, a professor and chair of McGill's Department of Physiology, stated that an aged thymus causes a "leaky" immune system. This raises the risk of autoimmune illnesses like Type 1 diabetes because the thymus is less able to filter out immune cells that can inadvertently target healthy tissues. He pointed out that scientists have long understood that vitamin D aids in the body's absorption of calcium for healthy bones, and that more recent studies have identified its critical function in immune system regulation. "Our findings provide fresh insight into this relationship and may result in novel approaches to autoimmune disease prevention," he stated. The thymus acts similarly in both species, therefore although though the study was done on mice, the results are applicable to human health, White continued. The significance of an alternative to sunlight The results, which were published in Science Advances, emphasize how crucial it is for kids in particular to get enough vitamin D. "Supplementation is essential in places like Montreal, where we stop producing the vitamin from sunlight between late fall and early spring," White added. "If you have a young child, it's important to consult with your health-care provider to ensure they’re getting enough." The discovery expands on a 2001 study conducted in Finland that tracked over 10,000 kids. It was discovered that children who received vitamin D supplements from an early age had a five-fold decreased risk of Type 1 diabetes later in life. According to White, Finland was a perfect case study to understand the nutrient's multiple functions because of its protracted winters of vitamin D. Using mice that were unable to synthesize vitamin D, researchers in the McGill study investigated the effects of the deficit on the thymus and utilized gene sequencing and cell analysis to determine how it affected the immune system. White notes that this has never been done before and plans to investigate in future research how vitamin D impacts the human thymus.