A quick assessment tool for Vitamin B12 insufficiency. One of the foundational causes is a lack of intrinsic Factor—a glycoprotein made by the stomach’s parietal cells. Intrinsic Factor is used further down the digestive cascade in the intestines so B12 can be absorbed. Nutrition that supports parietal cell health and provides supplemental B12 can help alleviate symptoms of B12 deficiency. Universal rights to reproduce this document.