What happens when you have a folic acid deficiency? Folic acid is an essential nutrient that plays a vital role in many bodily processes. A deficiency in folic acid can have significant impacts on a person's health, including anemia, birth defects, weakened immune system, digestive problems, and fatigue. https://www.quora.com/What-happens-when-you-have-a-folic-acid-deficiency/answer/Vikash-Sharma-2756