RDA Changes Expected : Nutrient Allowances to Be Altered
The Recommended Dietary Allowances, which are due for revision this year, will contain some changes that will affect nutrient recommendations for boys and girls and the elderly.
Speaking to nutrition educators at the 18th annual meeting of the Society for Nutrition Education at the Bonaventure Hotel last week, Helen A. Gutherie, Ph.D., head of the nutrition program at College of Human Development at Pennsylvania State University, said that the new RDAs, which should have already been released this month, are still undergoing a review process to concur with the Food and Nutrition Board of the National Academy of Sciences, from which the RDAs emanate.
New Data Considered
“Many of the changes were based on new nutritional data collected since the last RDAs were released in 1979 as well as a re-evaluation of existing data,” she said.
Once defined as a “formulation of nutrient allowances for daily consumption . . . adequate for the maintenance of good nutrition in essentially all the population of the United States,” the RDAs now will be defined as “levels of essential nutrients that, on the basis of available scientific knowledge are judged by the committee on dietary allowances to be adequate to protect practically all healthy individuals from nutritional deficiencies.”
The data base in developing the new RDAs include input from current food composition data, consumption studies, epidemiologic evidence of deficiency diseases, metabolic balance studies in humans, experimental studies in both human and animals, kinetic studies as well as studies in which subjects underwent nutrition depletion and repletion.
According to Gutherie, special considerations were given to nutrient interactions with other nutrients and substances, such as tobacco, alcohol
Age-Related Differences
Also under consideration are recommendations for different age categories and the allowances to be obtained through a varied diet for infants newborn to 2.9 years old, 3 to 5.9 years old and 6 to 11.9 years old. The 1979 RDAs were only for infants newborn to 6 months and 6 months to 1 year, and children 1 to 3 years, 4 to 6 years, 7 to 10 years.
Recommendations will differentiate between boys 10 to 11.9 years and 12 to 17.9 years and girls 10 to 14.9 years and 15 to 17.9 years because of different growth patterns and nutrient needs of each sex. The 1979 RDA lumped boys and girls in common categories of 11 to 14 years and 15 to 18 years.
Changes in recommendations for the elderly also will consider age groups within the elderly category. The previous RDAs took into account recommendations only for individuals 51 or older, whereas the revised RDAs divide the age groups between 50 to 69.9 years old and 70 years and up.
“We must consider physiological as well as chronological age differences,” Gutherie said. Consideration is based on decrease of nutrient absorption by elderly individuals as well as decrease in some nutrient requirements.
The changes also have to do with calories and some of the nutrients themselves--protein, Vitamin C, Vitamin B, zinc, iron and selenium. But these changes will not be divulged until the RDAs are released in September.
