According to a Dietitian

All of which are necessary for the body. While they share similarities each vitamin performs its. Difference Between Vitamin B And Vitamin B12 Vitamin B-12 is one of the eight B vitamins while B-100 also referred to as B-complex is a multivitamin supplement that contains high amounts of all the B vitamins. B complex vs.b12 . Ive given this combo to many people and the only side effect Ive seen is temp. However these levels are often fairly low since the RDI is typically only enough to avoid a deficiency. The B-complex vitamins include B1 B2 B3 B5 B6 B7 B9 and B12. Supplements that are marketed as B Complex Stress Formula tend to contain the eight B. Most supplements that are labeled B Complex contain all eight of the B vitamins whereas vitamin B-12 supplements only contains vitamin B-12. According to the University of Maryland Medical Center a vitamin-rich diet can help you stave off many diseases. B-complex supplements generally contain all eight though the most