Vitamin B12 plays an essential role in energy production by aiding in the formation of red blood cells and maintaining a healthy nervous system. It is crucial for synthesizing DNA and metabolizing fatty acids and amino acids, thus supporting overall cellular energy. A deficiency in B12 can lead to fatigue, weakness, and anemia, ultimately impacting physical performance and energy levels. Including adequate sources of B12 in the diet, particularly for those on plant-based diets, is vital to maintaining optimal energy production and preventing health complications.