bigger the difference between intake and EAR and the lower the variability of intakes and requirements, the greater the degree of certainty one has in assessing whether the individual’s nutrient intake is adequate or inadequate. This approach is preferred because of its relative accuracy and should be used when the data indicated above are available.
However, when the estimate of usual intake is not based on specific recalls or records, a more qualitative interpretation of intakes could be used. For example, many practitioners use the diet history method to construct a usual day’s intake, but the error structure associated with this method is unknown. Thus, a practitioner should be cautious when using this method to approximate usual intakes.
For practical purposes, many users of the DRIs may find it useful to consider that observed intakes below the EAR very likely need to be improved (because the probability of adequacy is 50 percent or less), and those between the EAR and the Recommended Dietary Allowance (RDA) probably need to be improved (because the probability of adequacy is less than 97.5 percent). Only if intakes have been observed for a large number of days and are at or above the RDA, or observed intakes for fewer days are well above the RDA, should one have a high level of confidence that the intake is adequate.
For example, a 40-year-old man who usually consumes 8 mg/day of zinc from his food and who takes a multiple vitamin and mineral supplement containing 15 mg of zinc 3 days a week would average 14.4 mg/day (8 mg + [15 mg × 3 ÷ 7]). Thus, his diet alone (8 mg/ day) would put him at a high risk of inadequacy since it is below the EAR of 9.4 mg/day. The addition of the supplement, however, provides an amount above the RDA of 11 mg/day, thus suggesting little likelihood that intake is inadequate if dietary assessment represents his true usual food and supplement intake. If this same man took his multiple vitamin and mineral supplement every day, his usual intake from supplements alone would exceed the RDA, and one could conclude that he has little likelihood of inadequate zinc intake even without knowledge of his intake of zinc from food.
Adequate Intakes (AIs) have been set for all nutrients for infants through 6 months of age. By definition and observation, infants born at term who are exclusively fed human milk by healthy mothers are consuming an adequate nutrient intake. Infants who are consuming formulas with a nutrient profile similar to human milk (after