Food Fortification, Nutrient Status, Deficiency, Adequacy and Safety
Children around the world are starving or being overfed and undernourished. Why? Because the foods they eat do not provide recommended amounts of essential nutrients – vitamins, minerals, essential fatty acids and amino acids. 165 million children suffer from chronic malnutrition that leaves them permanently stunted. They lack nutrients (iron, iodine, DHA, lutein) required for normal brain development.
Why is this relevant to the United States? Because fortified foods and beverages are important sources of vitamins and minerals. Children who do not consume fortified/enriched foods or use dietary supplements are more likely to fall below the Estimated Average Requirement (EAR). By choosing to eat only foods intrinsically rich in vitamins and minerals, many children will be nutritionally challenged: vitamin A (25%), vitamin D (100%), vitamin E (70%), thiamin (8%), niacin (4%), folate (57%), vitamin C (5%), calcium (25%), and iron (12%) (Berner et al, 2014).
The Tolerable Upper Level (UL) was developed by the Institute of Medicine in the late part of the 20th century. The UL is the highest average daily nutrient intake level likely to pose no risk of adverse health effects in almost all individuals. A UL is set for each age group. Typically, ULs were developed using extremely conservative safety factors from data acquired in adults. Assuming a linear relationship between UL and body weight, experts extrapolated adult ULs down to create ULs for children with an even greater margin of safety for the youngest ages.
In the US, 49.6% of children <2y of age and 17% of those 2-5y are using dietary supplements recommended by a physician or health care provider (Bailey et al, 2013). 78.7% of children and adolescents under 19y are using multivitamin and mineral supplements. Examining nutrient intake data from food and multivitamin/mineral supplements in children 4-8y of age, Wallace et al (2014) report only one nutrient (zinc) where more than 5% of children exceeding the UL. Other than one case report of a zinc-induced copper deficiency, there are no published studies on adverse effects of zinc in young children.
To paraphrase (almost verbatim) from Dwyer and associates (2014), fortification is a challenge. When a single food is fortified, it is not certain that everyone will benefit because some may not consume that food for one reason or another. It is possible that fortification may miss the intended population because individuals consuming the poorest diets may be less likely to eat the fortified foods. Fortification will increase nutrient consumption in those who eat the food product. The impact will be greatest in frequent users or those who eat larger amounts.
Since 1997 the Micronutrient Initiative has provided supplementation programs to deliver vitamin A, zinc, iodine, iron and folic acid to regions with the greatest need. Because of the prevalence of hunger worldwide, the World Food Programme provides food for more than 97 million people in 80 countries. Vitamin Angels strives to provide vitamins for women and their children who live in the remotest of regions. These supplementation programs and food fortification save lives.
Nutrient status of individuals cannot be accurately ascertained from dietary intake surveys. Nutrient inadequacy (or excess) needs to be determined using a validated biological marker. Dietary records and food frequency records are used as a surrogate for nutrient status measures in a person.
Investment is needed to develop mobile technologies to survey and monitor nutritional status. Rather than arguing about the benefits/dangers of specific foods and beverages which may not even be consumed by intended target groups, we should invest in measuring nutrient status with validated biomarkers. Congratulations to Aguilar and colleagues (2014) for validating a new method to measure skin carotenoids.
Using biomarkers, health professionals can identify individuals at risk of nutrient deficiency or excess. Rather than trying to maintain food databases and conduct dietary intakes in the entire population, health professionals should be measuring status and then surveying dietary practices in the subset at risk (low or high). Then health professionals, food manufacturers, and retailers could partner to educate, and adjust nutrient concentrations in heavily-used categories as needed, to ensure nutritional adequacy without excess.
Agarwal S, Labrique A. Newborn health on the line. The potential mHealth applications. 2014 JAMA doi: 10.1001/jama.2014.6371
Aguilar SS, Wengreen HJ, Lefevre M, Madden GJ, Gast J. Skin carotenoids: a biomarker of fruit and vegetable intake in children. 2014 JAND doi: 10.1016/j.jand.2014.04.026
Bailey RL, Gahche JL, Thomas PR, Dwyer JT. Why US children use dietary supplements. 2013 Ped Res doi: 10.1038/pr.2013.160
Berner LA, Keast DR, Bailey RL, Dwyer JT. Fortified foods are major contributors to food intakes in diets of US children and adolescents. 2014 JAND doi: 10.1016/j.jand.2013.10.012
Wallace TC, McBurney M, Fulgoni III VL. Multivitamin/mineral supplement contribution to micronutrient intakes in the United States, 2007-2010. 2014 JACN doi: 10.1080/07315724.2013.846806
Dwyer JT, Woteki C, Bailey R, Britten P, Carriquiry A, Miller D, Moshfegh A, Murphy MM, Smith Edge M. Fortification: new findings and implications. 2014 Nutr Rev doi: 10.1111/nure.12086