A crucial component that keeps bones strong and aids in calcium absorption throughout life is vitamin D. Eggs, seafood, dairy products, and UV rays from the sun are a few examples of the many foods that contain vitamin D. In the body, vitamin D goes through a number of processes. The body transforms it into a substance known as hydroxyvitamin D during the first transition that takes place throughout life. The best test to check the amount of vitamin D in the blood is the 25-hydroxy vitamin D total test. Whether the body has a high or low level of vitamin D is determined by the test. The test is a crucial early warning sign for osteoporosis and rickets.