The Health Library is a collection of health and wellness resources created for learning and accessibility. Select a topic below for related health information or search for a topic in the search bar for more information on other medical conditions.
Vitamin D Test
A vitamin D test measures the amount of vitamin D in the blood. Your body needs vitamin D to absorb calcium. Calcium keeps your bones and muscles healthy and strong. If your muscles don't get enough calcium, they can cramp, hurt, or feel weak. You may have long-term (chronic) muscle aches and pains. If you don't get...