Since 1941, Recommended Dietary Allowances (RDAs) has been recognized as the most authoritative source of information on nutrient levels for healthy people. Since publication of the 10th edition in 1989, there has been rising awareness of the impact of nutrition on chronic disease. In light of new research findings and a growing public focus on nutrition and health, the expert panel responsible for formulation RDAs reviewed and expanded its approach—the result: Dietary Reference Intakes.


This new series of references greatly extends the scope and application of previous nutrient guidelines. For each nutrient the book presents what is known about how the nutrient functions in the human body, what the best method is to determine its requirements, which factors (caffeine or exercise, for example) may affect how it works, and how the nutrient may be related to chronic disease.


This volume of the series presents information about thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, biotin, and choline.


Based on analysis of nutrient metabolism in humans and data on intakes in the U.S. population, the committee recommends intakes for each age group—from the first days of life through childhood, sexual maturity, midlife, and the later years. Recommendations for pregnancy and lactation also are made, and the book identifies when intake of a nutrient may be too much. Representing a new paradigm for the nutrition community, Dietary Reference Intakes encompasses:




Estimated Average Requirements (EARs). These are used to set Recommended Dietary Allowances.
Recommended Dietary Allowances (RDAs). Intakes that meet the RDA are likely to meet the nutrient requirement of nearly all individuals in a life-stage and gender group.
Adequate Intakes (AIs). These are used instead of RDAs when an EAR cannot be calculated. Both the RDA and the AI may be used as goals for individual intake.
Tolerable Upper Intake Levels (ULs). Intakes below the UL are unlikely to pose risks of adverse health effects in healthy people.


This new framework encompasses both essential nutrients and other food components thought to pay a role in health, such as dietary fiber. It incorporates functional endpoints and examines the relationship between dose and response in determining adequacy and the hazards of excess intake for each nutrient.

Table of Contents


Front Matter
Summary
1 Introduction to Dietary Reference Intakes
2 The B Vitamins and Choline: Overview and Methods
3 A Model for the Development of Tolerable Upper Intake Levels
4 Thiamin
5 Riboflavin
6 Niacin
7 Vitamin B6
8 Folate
9 Vitamin B12
10 Pantothenic Acid
11 Biotin
12 Choline
13 Uses of Dietary Reference Intakes
14 A Research Agenda
A Origin and Framework of the Development of Dietary Reference Intakes
B Acknowledgments
C Système International d'Unités
D Search Strategies
E Methodological Problems Associated with Laboratory Values and Food Composition Data for B Vitamins
F Dietary Intake Data from the Boston Nutritional Status Survey, 1981–1984
G Dietary Intake Data from the Continuing Survey of Food Intakes by Individuals (CSFII), 1994–1995
H Dietary Intake Data from the Third National Health and Nutrition Examination Survey (NHANES III), 1988–1994
I Daily Intakes of B Vitamins by Canadian Men and Women, 1990, 1993
J Options for Dealing with Uncertainties in Developing Tolerable Upper Intake Levels
K Blood Concentrations of Folate and Vitamin B12 from the Third National Health and Nutrition Examination Survey (NHANES III), 1988–1994
L Methylenetetrahydrofolate Reductase
M Evidence from Animal Studies on the Etiology of Neural Tube Defects
N Estimation of the Period Covered by Vitamin B12 Stores
O Biographical Sketches
P Glossary and Abbreviations
Index