Vitamins and supplements are recommended as an integral part of the Atkins diet due to the severe restriction of nutrients found in regular carbohydrates like fruit and vegetables. Atkins recommends about 30 different supplements, and even has a chapter dedicated to why they are so important in his diet.
This is a cause for concern, and the reality is that without these supplements, malnutrition would be a big problem. Fruit and vegetables are an important source of soluble and insoluble dietary fiber, as well as crucial phytonutrients and antioxidants, including lycopene, carotenoids, phytic acid, bioflavanoids, and others. Fiber is important in preventing heart disease, diabetes, and constipation. Phytonutrients have a range of benefits that include a cancer-protective effect, an anti-aging effect, and other specific health benefits.
Vitamin And Mineral
Whilst it is possible to get vitamins and minerals in a bottle, the enzymes (that help with digestion), and these other phytochemicals, are not so easily represented. Supplements are also a poor source of fiber. To get any significant amount of these from supplements is going to be an expensive option, and there is always the risk that the broad spectrum is not well represented.
There are some negative consequences of the Atkins diet that can affect the level of certain vitamins and minerals in the body - even if we are still losing weight. So, whilst it may seem like the short term goal (weight loss) is being met, there may be a health cost that becomes more apparent over time.
For example, a diet with high amounts of calcium and cheese, such as is encouraged by the Atkins diet, will result in a loss of calcium in the urine. This calcium is taken from our store of it in our bones. The acidity in meat and cheese upsets our internal pH balance, which then causes our body to remove calcium from the deposits in our bones in an effort to rebalance it.
This is borne out in the Harvard Nurse's study, where those nurses that ate more animal protein had significantly increased risks of fracturing their forearms. Other studies have shown a link between meat consumption and hip fracture. And a rather interesting study from 2002 by researchers at the University of Chicago and Texas found that after two weeks on the Atkins diet, people were losing 258 mg of calcium a day, in their urine. This loss of calcium in the urine in such quantities can lead to kidney stones forming. To make matters worse, the Atkins diet is deficient in calcium anyway - even with most of the recommended supplements.
This makes it particularly dangerous for long term usage, especially if you are in a risk group for osteoporosis.
There are other risks of the Atkins diet, but it is definitely not something to be undertaken without all of the supplements. Whether the increased cost of these supplements makes it worthwhile - or sufficiently mitigates the risks - is another question.
References: Atkins Exposed (website)