The B vitamins work together as a team. Some of them help cells burn fats and glucose for energy, while others help with the production of serotonin. They work intricately together behind the scenes with amazing results. Found naturally in meat, leafy greens, dairy, beans, peas, and whole or fortified grains, B-complex vitamins help your body make energy from the food you eat, form red blood cells, and play an essential role in certain bodily functions. Let's take a closer look at the benefits, signs of deficiency, and food sources for each of these B-complex vitamins.