The evidence is inconclusive to state that vitamins on their own help you to lose weight.
There is some evidence that certain minerals can aid weight loss. When 11 obese men increased their daily calcium intake from 447 to 1,029 mg per day (by adding 2 cups of yogurt a day) for a year, they lost an average 11 lbs. of body fat each. People with the least calcium in their diets are 6 times as likely to be fat.
There are other good reasons to take vitamins while dieting. When people are eating less food, they may need to add vitamins that they are no longer getting from food. Additionally, dieting results in water loss as well as the loss of some water-soluble vitamins and minerals. Lindora’s vitamins have been formulated to compensate for this loss. The most important difference between vitamins formulated for weight loss and commercial vitamins is in the additional minerals that are included.
 However, it is O.K. to substitute any vitamin with comparable dosages. Take the vitamins as directed.  FASEB 14(9)1, 132, 2000