AQA Food Preparation and Nutrition Practice Exam 2025 - Free Practice Questions and Study Guide

Folic acid, also known as vitamin B9, plays a crucial role in the production and maturation of red blood cells. It is essential for DNA synthesis and repair, which is particularly important during periods of rapid cell division and growth, such as during pregnancy and infancy. Folic acid works in conjunction with vitamin B12 to ensure the proper development of red blood cells and to prevent anemia. By facilitating the formation of healthy red blood cells, folic acid helps in maintaining optimal oxygen transport throughout the body, which is vital for overall health.

The other options refer to functions that are not primarily associated with folic acid. While there are vitamins and nutrients that contribute to immune system enhancement and brain function, these functions do not accurately describe the primary role of folic acid in the body.