VITAMIN D helps the body to perform vital functions. It is well understood that a lack of the nutrient can cause physical deformities. Mounting evidence suggests it may take its toll on emotional health too.Vitamin D is created from direct sunlight on the skin when outdoors. Vitamin D helps regulate the amount of calcium and phosphate in the body. These nutrients are needed to keep bones, teeth and muscles healthy. People that lack the vitamin may experience achy bones. A more subtle sign is a change in a person’s mood.