I recently came across a paper analyzing the micronutrient deficiencies in four popular diets – the South Beach Diet, the Atkins for Life Diet, the DASH diet, and the Best Life Diet.
According to this paper , none of these diets provides the RDA for more than 15 of the 27 micronutrients studied. Some nutrients were lacking in all four diets. The diets averaged:
- 58% of the RDA for pantothenic acid (vitamin B5).
- 29% of the RDA for biotin.
- 34% of the RDA for vitamin E.
- 56% of the RDA for choline.
- 9% of the RDA for chromium.
- 34% of the RDA for iodine.
- 73% of the RDA for potassium.
Of these I would take the chromium and iodine deficiencies very seriously. These would certainly merit supplementation – indeed, in our book they are among the 8 micronutrients we strongly recommend supplementing.
Cases can also be made for supplementation of others on this list:
- Biotin and pantothenic acid are harmless in very high doses, and extremely cheap – less than 4 cents for 500 mg pantothenic acid or 5 mg biotin.
- Choline deficiency is widespread and there is evidence that choline supplements are very helpful for pregnant women.
More important than any specific deficiency, however, is the implication for ordinary diets. If these comparatively healthy diets are deficient, then nearly any modern diet is likely to produce micronutrient deficiencies.
Agriculture – planting the same crops, year after year, in the same fields – tends to deplete the soil of nutrients, and hence both plant crops and crop-fed animals tend to be low in nutrition. Water treatment also removes minerals like calcium and magnesium from drinking water.
A British study, for instance, found that copper levels in UK foods have declined by 76% in vegetables, 90% in dairy foods, and 55% in meat.  Some other nutrients have declined nearly as much.
It’s important to take some care, therefore, to eat a nourishing diet. Especially nourishing foods include seaweed, green leafy vegetables, organ meats including liver, and seafoods.
Cooking style is also important: Cooking should be done in a way that doesn’t throw away drippings from foods, but rather preserves them as a sauce or soup. Also, very high cooking temperatures which can destroy or denature nutrients should be avoided.
Even with these steps, supplementation is probably necessary for optimal health. We recommend taking a daily multivitamin plus a few other supplements, notably including iodine, magnesium, vitamin D, and vitamin K2.
 Calton JB. Prevalence of micronutrient deficiency in popular diet plans. J Int Soc Sports Nutr. 2010 Jun 10;7(1):24. http://pmid.us/20537171. Full text: http://www.jissn.com/content/pdf/1550-2783-7-24.pdf.
 Thomas D. The mineral depletion of foods available to us as a nation (1940-2002)–a review of the 6th Edition of McCance and Widdowson. Nutr Health. 2007;19(1-2):21-55. http://pmid.us/18309763. Hat tip Robert Andrew Brown, http://wholehealthsource.blogspot.com/2010/04/copper-and-cardiovascular-disease.html.