D is different from other essential vitamins because the human body can manufacture it with exposure to sunlight. The main function of vitamin D is to regulate the absorption of calcium and phosphorus in our bones and aid in cell-to-cell communication throughout the body.
If you don’t get enough D, you’re at risk for developing bone abnormalities such as osteomalacia, which is soft bones, and osteoporosis, or fragile bones.
According to studies published by the American Journal of Clinical Nutrition, vitamin D reduces the risk of multiple sclerosis, decreases the chance of developing heart disease and helps to prevent the flu.
Foods rich in vitamin D include, salmon, sardines, egg yolk, shrimp, fortified milk and yogurt, fortified cereal and fortified orange juice. You can also supplement vitamin D—but a little bit of fun in the sun goes a long way to D-rail illness!