The B-vitamin family includes eight closely related, water-soluble vitamins that play a variety of important roles in your body. These include regulating hormone levels, helping produce enzymes and encouraging neurological health. Because they play roles in converting food to energy, taking B vitamins can aid your efforts to lose weight through diet and exercise. However, taking B vitamins will not, on its own, cause weight loss.
One of the major functions of B vitamins is to break down carbohydrates into glucose. Some B vitamins then help to convert glucose to adenosine triphosphate, which is the major form of energy fueling your body. In addition, some B-vitamins help to convert fat and protein in food to energy. Despite these important roles in fueling your attempts to lose weight through exercise, there is no link between taking B vitamins and weight loss.