Are You ABCDE-Deficient? Common Nutrient Deficiencies in the US. Plus: How Food Fortification & New "Daily Values" Affect the Intakes of Vitamin A-E, Calcium Iron & Co

Nutrition labels on fresh blueberries - do we really need them?

I sill remember that I was shocked, when I bought a pack of blueberries and found a nutrition label underneath the plastic cover of my expensive 150g health-investement...

That's probably 2 months ago and the reason I do remember this event now is the publication of a paper that examines the effect a change in the "daily values" (i.e. the references), the figures in the obiquitous black and white table are based on, would have on the average US citizen's nutritional intake of the vitamins A, D, E, C, B-12 and folate, and the minerals calcium and iron.
According to the data Mary M. Murphy and her colleagues from the National Institutes of Health/Office of Dietary Supplements present in their latest paper, there is still a large gap between the current DV values, which represent the RDAs (recommended daily allowances) from 1968 and have been matched to

"the highest level of intake judged to be adequate to meet the known nutrient needs of practically all healthy persons in a specific age-gender group" (Murphy. 2013)

on the one hand, and supposedly "improved" candidates that could replace them: The population weighed and the population coverage varieties of the RDA & EAR.

• RDA = the average daily dietary nutrient intake level that is sufficient to meet the nutrient requirements of nearly all (97–98%) healthy individuals in a particular life-stage and gender group
• EAR = the average daily nutrient intake level that is estimated to meet the requirements of half of the healthy individuals in a particular life-stage and gender group

As you can see in Table 1 these new recommendations are not - as you may have expected -  significantly higher than the current daily values. If you look closely, you will in fact notice that some of them are significantly lower!

Table 1: Current DVs for select vitamins and minerals and potential DVs based on population-weighted and population-coverage RDAs and EARs. AT,a-tocopherol; DV, Daily Value; EAR, Estimated Average Requirement; RAE, retinol activity equivalent; RE, retinol equivalent (Murphy. 2013).

In the case of vitamin B12 and copper, for example, the difference between the "reformed" recommendations would amount to -50%. The population-coverage RDA for vitamin C, on the other hand, is 50% higher than the old "daily values" (DV) and still more than 10x lower than the 1,000mg of ascorbic acid, of which you may have read on the Internet that it was the bare minimum intake of vitamin C (more about vitamin C).

Figure 1: Percentage of U.S. population aged >4y with dietary intakes below the EAR based on current intakes and assuming constant %DVs in fortified foods under the current, as well as two potential DV scenarios, i.e. the population-weighed EARs or the population-coverage RDAs become the revised DV values (Murphy. 2013)

Irrespective of the "low" RDA and the high number of fortified foods, ascorbic acid is yet still one of the those micro-nutrients the diets of more than 40% of the US are deficient in. And as the overview in Figure 1 goes to tell you, this would not change, if any of the new RDAs or EARs became the new DVs, so that the amounts of vitamin C in fortified food was adjusted.

Not an improvement by any means

In a more thorough sub-analysis, the scientists observed that the differences in the proportion of the total population with usual intakes less than the EAR would be <2% of 5 out of 8 nutrients (vitamins D, E, and B-12; folate; iron), regardless of whether the policy makers sued the population weighted EARs or the population-coverage RDAs as a basis for the revision of the DVs.

To put it plainy: This means that the micronutrient intake of more then 3 million individuals would still fall below the EAR in the total population (U.S. Census Bureau. 2005).

Even worse, if someone in the upper echolons was bribed.... ah, I mean convinced by the conclusive evidence we have that using the population-weighted EARs instead of the population coverage RDA would be the best thing to do, this would increase the risks of inadequate iron and folate intake in women of childbearing age. Both, iron and folate deficiency, can result in irreversible damage to the unborn child (Scholl. 2000; McArdle. 2013). The same is true for vitamin A (Wallingford. 1986) of which Murphy et al. write that it "was identified as a shortfall nutrient (although intakes are not currently in the category ‘‘of concern’’) for the U.S. population" (Murphy. 2013).

References:

• McArdle, Harry J., Lorraine Gambling, and Christine Kennedy. "Iron deficiency during pregnancy: the consequences for placental function and fetal outcome." The Proceedings of the Nutrition Society (2013): 1-7.
• Murphy, Mary M., et al. "Revising the Daily Values May Affect Food Fortification and in Turn Nutrient Intake Adequacy." The Journal of nutrition 143.12 (2013): 1999-2006.
• U.S. Census Bureau. 2005 Middle series data from annual projections of the resident population by age, sex, race, and Hispanic origin: lowest, middle, highest, and zero international migration series, 1999 to 2100 (NP-D1-A). Washington: Department of Commerce; 2000 [cited 2012 Jun 16]. Available from: http://www.census.gov/population/www/projections/natdet-D1A.htm 
• Scholl, Theresa O., and William G. Johnson. "Folic acid: influence on the outcome of pregnancy." The American journal of clinical nutrition 71.5 (2000): 1295s-1303s.
• Wallingford, J. C., and B. A. Underwood. "Vitamin A deficiency in pregnancy, lactation, and the nursing child." In: Bauernfeind JC, ed. "Vitamin A deficiency and its control." New York: Academic Press, 1986:101–52.