Annemarie Colbin, in her book "Food and Healing", makes the interesting point that diets themselves, even healing diets, are not a cure per se. They do often work, but their route to health is actually a product of supporting the body's own healing processes.
Her view on skin conditions like acne is interesting. She sees acne as a result of the regular organs of elimination, the kidneys and lungs, being unable to eliminate all the toxic waster matter that we ingest into our bodies. She sees certain foods, like those that make up what she calls the Standard American Diet, as placing too great a stress on our body's ability to process them, at least if symptoms of ill health are appearing like acne.
She has found from her own observations that a change in diet often clears up even the large, purplish types of acne. She found this with her own experiences with acne. Annemarie says it takes about ten days to three months to work.
Annemarie describes acne as falling into two main causes in her approach.
The first is associated with fat, protein and excess sugar. Here she recommends eliminating foods like milk, cheese, ice cream, fatty meats, nuts and peanut butter. T
he second category is associated with what she calls mineral-water excess, which is s term she uses to describe all substances taken out of their natural context. She mentions iodized salt, or even multi vitamins or supplements like kelp. This is very much a personal relationship as what negatively affects one person may not do so for another.
The link between excess minerals or vitamin supplements relates to Colbin's idea of balance, which is that a living system always seeks to return to balance. Anatomy and physiology textbooks even define the processes of the body that way, and it is certainly a common idea in natural health systems, especially traditional Chinese medicine (TCM). Colbin writes that excess minerals and vitamin supplements lead to an increased need for the macro nutrients protein, fat and carbohydrates. Salt is also in this category. The idea is that these vitamins and minerals, taken out of the context of the food itself, will lead to the body craving actual food to create a sense of balance.
If we have a multi vitamin at mealtimes, within the RDA, I don't believe this is going to present a problem. Especially given that our foods are often depleted of the range of essential nutrients that they would normally have if they were grown organically and in nutrient dense soils. But it is certainly an argument in favor of approaching nutritional supplements in a balanced way also. Some people mistakenly think more is better. This clearly illustrates it is not.
References: Annemarie Colbin, Food As Healing (Ballantine Books, New York)
Simon Mills, The Essential Book Of Herbal Medicine (Penguin Arkana)