Chapter 1: Introduction Chapter 2: What is Vitamin D Chapter 3: What is Vitamin D Deficiency Chapter 4: How do You Test for Vitamin D Chapter 5: When Should Vitamin D Testing be Done Chapter 6: How Much Vitamin D Should be Ordered Chapter 7: How Long Does Vitamin D Last Chapter 8: What are the Precautions with Vitamin D Chapter 9: Are There Any Toxic Effects Chapter 10: How Much Does Vitamin D Cost Chapter 11: Summary Chapter 12: References