5. Celiac Disease
Celiac disease is an autoimmune disease that causes the immune system to attack and damage the small intestines when gluten is consumed. Due to the damage, the small intestines are not able to absorb nutrients very well. A gluten free diet allows the intestines to heal so vitamins and minerals can be absorbed. However, if you have celiac disease, you should talk to your doctor about possible deficiencies that may need to be addressed.