Adreno,
Your question is the "theory" I have been trying to write - what caused it. I believe it was the World Health Orginization that set up the imbalance, but all of you can judge for yourself after you read how I've put it together. I've touched on many of the reasons like taking too much of one kind of supplement. Most recent research even shows that possibly the amount of folic acid enrichment may have caused problems (I completly agree).
http://www.ajcn.org/content/86/1/159.full
American Journal of Clinical Nutrition, Vol. 86, No. 1, 159-166, July 2007
2007 American Society for Nutrition
Effect of folate oversupplementation on folate uptake by human intestinal and renal epithelial cells1,2,3
Balasubramaniem Ashokkumar, Zainab M Mohammed, Nosratola D Vaziri and Hamid M Said
1 From the Department of Medicine, Division of Nephrology (BA, ZMM, NDV, and HMS) and the Department of Physiology and Biophysics (NDV and HMS), University of California, Irvine, CA, and the Department of Veterans Affairs Medical Center, Long Beach, CA (BA and HMS)
2 Supported by grants from the National Institutes of Health (DK58057 and DK075348) and the Department of Veterans Affairs.
When you become ill, or take various medications, the body has xenobiotics (foreign things like a virus) that have entered it. Thus the body has to detoxify these things via the liver. This requires many nutrients to be used correctly. But when you understand the thousands of enzyme reactions that riboflavin overseas, you begin to track backward from most instances of health imbalance to a level of B2 that just got too low.
As I wrote before, Professor Gallaher does not agree with me that the "balance" is critical to optimal health. But I believe it is. Once you experience how your body feels when it is adequately producing ATP, you very quickly know when the balance again is off. I think people have to learn more about nutrients and what symptoms indicate deficiency. Also how they interact. This helps a person guide their own way in choosing what foods they should eat to bring the balance back. One thing that Professor Gallaher and I do agree on though is, if your body is in balance, then one should always constantly vary what natural foods you eat so you obtain all nutrients (known and unknown).
Each food, if you look it up on the USDA nutrieint data base
http://ndb.nal.usda.gov/ndb/foods/list will show you the breakdown of each food. If you use this regularly, you will learn what foods are high in various nutrients and what are low. All foods differ, but some slant to being very high in one things. I will say though, that God seemes to have designed most foods to balance themselves. For example, lobster is very high in copper, but also very high in Omega 3's which remove copper. Some foods that are very high in iron are also very high in phytic acid which binds it and lowers its absorption. So there is normally a balance to foods. Some not so like brazil nuts that have an incredibly high level of selenium. This I believe is the reason for the high "allergy" response to it.
In my opinion, I believe when man tampered with the balance of foods, by enriching them, it was not a good thing. Their knowledge of nutrition was what it was at the time, but I believe they made a wrong decision based on lack of knowledge in 1939. Foods preserved with ascorbic acid (vitamin C) cause a change in non heme iron (the kind in foods that is hard to absorb) to heme iron (the kind that is easy to absorb). So just what seemed like a simple thing to preserve a food with a "natural" substance, can dramatically affects your health. This is just one instance of changing the balance of our foods.
I always advise all my clients, if they want to work with me they can no longer eat enriched products. That is nearly impossible in the US for dairy - as Vitamin A is in most, except greek yogurts, but hopefully once this information gets out, the World Health Orginization will make changes and our lives can go forward healthier.
I will say that hair testing has been the best way I've been able to track my dogs, husband and my balance. I do know when I take too much of one nutrient or get busy and eat the same food several days in a row - I again do not feel optimal. But I check our charts fairly often to observe which way I swayed our balance. Sometimes it's even difficult for me to tell, but the more experience I get at using them, the better I become at understanding them.