Multivitamin

• One of the most important supplements anyone can take, but especially on the Atkins diet, is a multivitamin. It is difficult, if not impossible, to obtain all the necessary vitamins and minerals from diet alone. This is even more so when your diet is restricted to primarily proteins. Taking a multivitamin during the induction and other phases of the Atkins diet is essential, but if you use a chewable be sure to consider whether it contains any carbs.
  
  

Phytonutrients and Enzymes

• Somewhat less essential, but still important, are supplements containing phytonutrients and digestive enzymes. Phytonutrients include the antioxidants, sterols and other molecules usually obtained from fresh fruits and vegetables. Plant-derived supplements containing these nutrients can be an important part of maintaining your health while on a low-carb diet. Supplements containing digestive enzymes can help your body adjust to the change in your diet. Amylase is crucial for digesting carbs. On a low-carb diet, you might need supplemental protease and lipase to break down protein and fat respectively.
  
  

Laxatives

• Completely discretionary, but sometimes very important, is use of laxative supplements during low-carb diets. As any low-carb dieter will notice, high protein foods such as meats are low in fiber and move slowly through the digestive tract. Constipation is not uncommon, especially because it is recommended that coffee and other sources of caffeine, the world's favorite laxative, be excluded during the induction phase. Fiber laxatives that do not contain net carbohydrates are acceptable on low-carb diets.