How Much is Too Much?

Excess Vitamins and Minerals in Food Can Harm Kids’ Health

June 19, 2014

How Much is Too Much? : How Much Is Too Much?

For 1-to-3-year-olds, a single serving of food containing 20 percent of the adult Daily Value of vitamin A, zinc and niacin provides the full recommended dietary allowances of vitamin A and zinc and two-thirds of the recommended niacin intake. Avoiding excessive intakes is particularly important for children younger than 4 because their tolerable intake limits are low, reflecting their lower body weight.
 
For 4-to-8-year-old children, a single serving of cereal containing 20 percent of the adult Daily Value of vitamin A, zinc or niacin provides 50-to-75 percent of the recommended daily dietary allowance (Table 7). The Institute of Medicine defines Recommended Dietary Allowance as the amount that provides the nutrient needs of 97-to-98 percent of healthy individuals in a particular age group. 

Table 7: One serving with 20 percent of the adult Daily Value (DV) of certain nutrients supplies half or more of the Recommended Dietary Allowance (RDA) for 4-to-8-year-old children and the complete or nearly complete RDA for 1-to-3-year olds

Fortified nutrient

Amount in one serving containing 20% of the adult DV

RDA for 1-to-3-year olds

Percentage of RDA for a
1-to-3-year-old from a single serving with 20% of the adult DV

RDA for
4-to-8-year- olds

Percentage of RDA for a 4-to-8-year-old from a single serving with 20% of the adult DV

Vitamin A*

1,000 IU (300 mg RAE)

300 mg/d RAE

100%

400 mg/d RAE

75%

Zinc

3 mg

3 mg/ day

100%

5 mg/ day

60%

Niacin

4 mg

6 mg/ day

67%

8 mg/ day

50%

* The current FDA daily value for vitamin A is expressed in the outdated form of international units (IU). 1,000 IU correspond to 300 mg (micrograms) of retinol activity equivalents (RAE), a measure for expressing vitamin A activity.

So long as outdated adult Daily Values are used for nutrition labeling, foods fortified with 50-to-100 percent of the adult Daily Value of vitamin A, zinc or niacin in a single serving pose the highest risk of overexposure for children 8 and younger. For pregnant women, foods with 50 percent or more of the adult Daily Value for vitamin A are also a risk, because ingesting excessive vitamin A during pregnancy can cause developmental defects in the fetus.
 
An additional complicating factor is that some cereals may contain more added vitamins and minerals than the label reflects, a situation that the 2003 Institute of Medicine report highlighted as a potential source of unsafe exposures (IOM 2003; UK EVM 2003). These “overages” occur when manufacturers deliberately add extra nutrient, either to ensure that it will be at the advertised level throughout the product’s shelf life or to compensate for expected breakdown of unstable vitamins (Ottaway 2008). 
 
Overages vary depending on the stability of the added ingredient. Unstable nutrients, such as vitamin A, generally require high overages (Wirakartakusumah 1998). Larger amounts are also sometimes added accidentally, which can cause illness (FDA 2014d). In 2001 Metabolife International recalled 1.5 million Diet & Energy Bars because they contained excessive amounts of vitamin A (Associated Press 2001), and in 2014 Mars Foodservices recalled the Uncle Ben’s Infused Rice products that were accidentally fortified with too much niacin (Sun 2014).
 
Studies in the U.S., the European Union and New Zealand have found that the actual level of fortified nutrients can be as much as double the amount on the label (Samaniego-Vaesken 2010; Thomson 2005; Thomson 2006; Thomson 2007; Whittaker 2001). A Dutch study published this year (2014) identified one fortified food that contained four times the amount of vitamin A listed on the label (Brandon 2014). In cereals that claim to provide 50-to-100 percent of the adult Daily Value, these “overages” can pose a significant health concern for young children, pregnant women and older adults.