How Much is Too Much?

Excess Vitamins and Minerals in Food Can Harm Kids’ Health

June 19, 2014

How Much is Too Much? : Appendix B: Vitamin and Mineral Deficiencies in the U.S.

Some American adults get too little vitamin D, vitamin E, magnesium, calcium, vitamin A and vitamin C (Table B1). More than 40 percent of adults have dietary intakes of vitamin A, C, D and E, calcium and magnesium below the average requirement for their age and gender.

Inadequate intake of vitamins and minerals is most common among 14-to-18-year-old teenagers. Adolescent girls have lower nutrient intake than boys (Berner 2014; Fulgoni 2011). But nutrient deficiencies are rare among younger American children; the exceptions are dietary vitamin D and E, for which intake is low for all Americans, and calcium. Approximately one-fifth of 2-to-8-year-old children don’t get enough calcium in their diets, compared to a half of adults and four-fifths of 14-to-18-year-old girls.

Table B1: Ranking of vitamins and minerals according to the degree of dietary inadequacy among adults. Nutrients from food alone include those that are naturally occurring; those used for mandatory enrichment of certain products, such as enriched flour and grain products; and those used for voluntary fortification.

Nutrient from food alone, ranked by the occurrence of dietary inadequacy among adults

Percentage of dietary intakes below the estimated average requirement for a specific population*

Naturally occurring sources of nutrient**

2-to-8-year-old children

14-to-18-year-old girls

Adults 19 and older

Vitamin D




Fatty fish, mushrooms [vitamin D is naturally formed in the body when skin is exposed to sunlight; vitamin D is added to fortified milk]

Vitamin E




Nuts, seeds, vegetable oils, green leafy vegetables





Whole grains, wheat bran and wheat germ, green leafy vegetables, legumes, nuts, seeds

Vitamin A




Preformed vitamin A: liver, fatty fish, milk, eggs; provitamin A carotenoids: carrots, pumpkins, tomatoes, leafy green vegetables





Milk, yogurt, cheese, kale, broccoli

Vitamin C




All fruits and vegetables, particularly citrus fruits and tomatoes

Vitamin B6




Many foods; highest levels in fish, beef, poultry, potatoes and other starchy vegetables, and fruit other than citrus





Many foods; highest levels in spinach, liver, asparagus, Brussels sprouts [mandatory, standardized addition to enriched flour and flour products]





Red meat, poultry, beans, nuts, some seafood, whole grains





Highest amounts in meat and seafood; lower levels in nuts and beans [mandatory, standardized addition to enriched flour and flour products]





Whole grain products [mandatory, standardized addition to enriched flour and flour products]





Shellfish, whole grains, beans, nuts, potatoes, organ meats (kidneys, liver)

Vitamin B12




Animal products: fish, meat, poultry, eggs, milk





Milk and dairy products, eggs, meat, green leafy vegetables, legumes [mandatory, standardized addition to enriched flour and flour products]





Meat, fish, seeds and nuts, whole grains [mandatory, standardized addition to enriched flour and flour products]





Found in different plant and animal foods; highest levels in seafood and organ meats (kidneys, liver)

* Dietary intake information originally derived from the National Health and Nutrition Examination Survey (NHANES). For children and adolescents, data from Berner 2014. For adults, data from Fulgoni 2011. All percentages greater than 1 were rounded to a whole number. Phosphorus data were excluded. According to Fulgoni 2011, 17 percent of 2–to-18-year-old children and adolescents and 2 percent of adults have phosphorus deficiency. There are many hidden sources of phosphorus in American diet, such as food additives in processed food (Uribari and Calvo 2003). Berner 2014 and Fulgoni 2011 did not account for this hidden phosphorus because, according to a publication from the FDA Center for Food Safety and Applied Nutrition, nutrient content databases and software programs currently used in large population studies do not consider these additional sources (Calvo and Uribarri 2013).
** Information on the dietary sources of vitamins and minerals from the website of the National Institutes of Health Office of Dietary Supplements

EWG compared the occurrence of vitamin and mineral deficiencies among Americans with our findings on vitamin A, zinc and niacin fortification levels in two of the most commonly fortified foods, ready-to-eat breakfast cereals and snack bars.


Zinc deficiency is rare in the United States, with only 10 percent of all Americans aged 2 and older having intakes below the estimated average requirement (Fulgoni 2011). The dietary needs for zinc can be addressed through natural sources and, as an alternative, low levels of fortification. Yet, as EWG found, 3 percent of cold cereals have zinc fortification levels at 30 percent or more of the adult Daily Value, and nearly a third of cold cereals have zinc fortification at 20-to-25 percent of the adult Daily Value. The FDA classifies such fortification levels as “high” (FDA 2004). The result of high zinc fortification of breakfast cereals, a food commonly eaten by children, is that 13-to-17 million American children are ingesting amounts of zinc that exceed the tolerable upper intake levels set by the Institute of Medicine.


Niacin is one of five nutrients (together with thiamin, riboflavin, iron and folate) whose addition is mandatory in all flour and flour products labeled “ enriched."  The enrichment is common practice for products sold in the U.S. because flour products, particularly bleached white flour products, lose a lot of essential vitamins and minerals during processing*. The standardized flour enrichment dramatically reduces the occurrence of inadequate intake of these five nutrients. Among all Americans older than 2, less than 2 percent get too litle niacin; 2 percent get too little riboflavin; 6 percent get too little thiamin; 7 percent get too little iron; and 11 percent get too little folate.

The low occurrence of inadequate intake of the nutrients added to processed grain products testifies to the success of the currently mandated flour enrichment policy (Yamini 2012). However, food manufacturers add much higher amounts to many processed foods than is required by law. EWG identified 20 cereals that add 100 percent of the adult Daily Value for multiple vitamins and minerals in a single serving. Sixty-seven percent of cold cereals and 64 percent of instant hot cereals fortify niacin to 20 percent or more of the adult Daily Value. As a result of this excessive fortification, nearly 5 million children ingest niacin in amounts exceeding the tolerable upper intake levels set by the Institute of Medicine.

Vitamin A

Some Americans get too much Vitamin A while others get too little. On one side, more than half of American adults and American teenagers have low dietary vitamin A intake (Berner 2014; Fulgoni 2011). On the other side, at least 13 percent of children 8 and younger ingest vitamin A in amounts exceeding the tolerable upper intake level set by the Institute of Medicine. Adequate intake of vitamin A is essential for good health, but excessive intake of preformed vitamin A from fortified foods and supplements are dangerous for infants, children, pregnant women and older adults. The difference between the necessary and the toxic amount is smaller for vitamin A than for many other vitamins.

Standardized vitamin-A fortified foods such as milk and butter spreads can be a good vehicle for providing the necessary amounts of vitamin A to people who might lack it in their diet, but great care must be exercised to avoid excessive vitamin A in children. The safest way of getting vitamin A is in the form of provitamin A carotenoids found in bright orange and yellow vegetables, tomatoes and green leafy vegetables (Tanumihardjo 2013). In contrast, eating cereals or snack bars with high levels of preformed vitamin A such as retinyl palmitate or retinyl acetate can easily lead to excessive exposures in young children and pregnant women.


* This page was updated May 29, 2018