Gastric juice is a digestive fluid produced by the stomach. It primarily consists of hydrochloric acid, pepsinogen, and intrinsic factor. The hydrochloric acid helps break down food and creates an acidic environment that activates pepsinogen into pepsin, an enzyme that digests proteins. This fluid plays a crucial role in digestion by breaking down food particles and killing harmful bacteria. The intrinsic factor is essential for the absorption of vitamin B12, which is vital for red blood cell production and overall health. Proper gastric juice production is important for effective digestion and nutrient absorption.