B Vitamins 101: Functions, Food Sources, and Daily Requirements

Nutrition Notes Explore all eight B vitamins, their functions, best food sources, daily requirements, deficiency risks, and preferred supplement forms for optimal health. CASI Editorial Team Jun 25, 2026 When people think about vitamins, the B vitamins often get grouped together in one category, when in reality they are a family of eight distinct nutrients, each with its own function. These vitamins work behind the scenes to help turn food into usable energy, build healthy red blood cells, support the nervous system, and keep important processes like methylation running smoothly. Methylation is a fundamental process the body relies on for everything from building DNA to regulating mood and detoxification, and several B vitamins, including B2, B6, B9, and B12, work together to keep it running smoothly. Because the B vitamins are water-soluble, the body does not store most of them in large amounts, meaning a steady supply is required from the diet. Whether the goal is more energy, sharper focus, or simply covering nutritional bases, understanding what each B vitamin does and where to find it is a practical place to start. What Are the B Vitamins and How Do They Work? The B vitamins a...