2. B Vitamins A group of vitamins that includes B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), B9 (folate), and B12 (cobalamin). B vitamins are vital for energy production, brain function, and cell metabolism. Small breed dogs benefit from these vitamins through a diet that includes lean meats, eggs, and whole grains.