Emerging Concepts in Nutrient Needs

Abstract

Dietary reference intakes (DRIs) are quantitative, nutrient intake-based standards used for assessing the diets and specific nutrient intakes of healthy individuals and populations and for informing national nutrition policy and nutrition programs. Because nutrition needs vary by age, sex, and physiological state, DRIs are often specified for healthy subgroups within a population. Diet is known to be the leading modifiable risk factor for chronic disease, and the prevalence of chronic disease is growing in all populations globally and across all subgroups, but especially in older adults. It is known that nutrient needs can change in some chronic disease and other clinical states. Disease states and/or disease treatment can cause whole-body or tissue-specific nutrient depletion or excess, resulting in the need for altered nutrient intakes. In other cases, disease-related biochemical dysfunction can result in a requirement for a nonessential nutrient, rendering it as conditionally essential, or result in toxicity for a food component at levels usually tolerated by healthy people, as seen in inborn errors of metabolism. Here we summarize examples from a growing body of literature of disease-altering nutrient requirements, supporting the need to give more consideration to special nutrient requirements in disease states.

Keywords: Dietary Reference Intakes; chronic disease; inborn errors of metabolism; prevention; special nutrient requirements.

FIGURE 1

Generic analytic framework applicable to assessment of nutrients. The representation illustrates how a nutritional exposure (intake) can directly affect a chronic disease outcome (Path I); how a nutritional exposure can directly affect a validated surrogate outcome that is on the causal pathway of a chronic disease outcome (Path II); how a nutritional exposure can directly affect a nonvalidated intermediate marker that is associated with a chronic disease outcome (Path III); how a nutritional exposure can directly affect a marker of nutrient intake that is associated with a chronic disease outcome (Path IV) and/or a surrogate outcome (Path V). Reproduced with permission from Russell et al, 2009 (11).

FIGURE 2

Factors and their associated pathways that affect human nutritional requirements in disease.