Neither B12 nor a B-complex supplement is universally "better," as their effectiveness depends entirely on your specific nutritional requirements and health profile. If you have been diagnosed with a targeted deficiency in cobalamin—common among vegetarians and older adults—a dedicated B12 supplement is required. Conversely, if you want comprehensive nutritional support for general energy metabolism, stress management, and overall cellular function, a balanced B-complex providing all eight essential B vitamins is the superior choice.