O Nutrition and Health

Table l-2 (continued)

1843

1848

1849-57

1850

1850-52

186641

1867

1877

1885

18%

1897

1902

1909-28

1912

1914

1916

1918

1919-22

1921-24

1922

1928

1929

1931-37

1932

1933

Chossat studied the effect of starvation on the body using
pigeons.

Addison described pernicious anemia.
Bernard elucidated digestive action of pancreatic juices and
glycogenic function of liver.

Livingstone described xerophthalmia (due to vitamin A
deficiency) in Africa.

Chatin in France used iodine to prevent goiter.
Voit and Pettenkofer explained protein metabolism.
Boussingault recognized iron as essential nutrient.
Pavlov began classic studies on digestion in dogs.
Takaki demonstrated in controlled dietary experiments with
Japanese Navy sailors that beriberi could be prevented.
Atwater and Bryant introduced their basic reference, Chemical
Composition of American Food Materials.
Eijkman published his work on causes of beriberi.
Rubner showed that food components increased metabolism by
different amounts.

Osborne and Mendel studied the nutritive value of protein.
Funk coined the term "vitamine."
Goldberger established dietary cause of pellagra.
McCollum and Davis and Osborne and Mendel discovered
accessory dietary factors "fat-soluble A" and "water-soluble B."
Mellanby showed that experimental rickets in dogs is due to lack
of fat-soluble vitamin.

Water-soluble B factor shown to be more than one factor.
Blindness in children shown to be result of lack of vitamin A.
McCollum identified vitamin D in cod liver oil.
Goldberger identified pellagra-preventing factor in yeast.
Role of intrinsic and extrinsic factors in pernicious anemia
discovered.
Fluoride content of drinking water identified as cause of mottled
enamel of teeth and prevention of tooth decay.
Vitamin C isolated from lemon juice. Warburg and Christian
identified riboflavin and defined its molecular function.
Williams identified kwashiorkor as a nutritional disease.

26


Introduction and Background O

Table l-2 (continued)

1938

1941

Rose classified amino acids as essential and nonessential.
Evidence provided for the influence of prenatal diet on the health
of the newborn infant.

! 944-46

Keys and coworkers studied effects on young men of
experimentally induced semistarvation and methods of dietary
rehabilitation.

I945


1948-49

Grand Rapids. Michigan. becomes the first city in the world to
fluoridate its drinking water to prevent tooth decay.
Crystalline vitamin B,, isolated from liver extract and shown to
contain cobalt.

1949     Framingham Study of coronary heart disease risk factors begins.
Sources: Darby 1985; McCollum 1957; Murlin 1948; Olson 1978; Todhunter 1962, 1973,
     1976.

food ingested (Lusk 1933). In the 19th century, European and American
scientists isolated and began to identify the major groups of nutrients in the
diet, to develop the first estimates of nutrient requirements, and to explore
the basics of energy metabolism. For example, in 1816, Magendie of
France established that nitrogen-containing compounds were essential in
the diet of dogs; in 1838, these compounds were given the name protein
(from the French word for "primary substance"). In 1814, the French
chemist Chevreul discovered that fats consisted of fatty acids attached to a
glycerol molecule. By 1834, the London physician Prout was able to
introduce the idea that food consists of substances called saccharine, oily,
and albuminous-today called carbohydrates, fats, and proteins
(Todhunter 1959). Later in the century, Rubner ofGermany and Atwater of
the United States established the energy values of these substances as
approximately 4, 9, and 4 kcal/g, respectively (McCollum 1957).

Thus, from the time of Lavoisier to the end of the 19th century, knowledge
of nutritional science grew to encompass the metabolic basis of energy
production from food, the classification of nutrients and sources of energy,
the dependence of energy requirements on physical activity, the influence
of diet on body weight and of fevers on metabolism of food substances, the
principles of metabolic homeostasis, and the roles of specific essential
nutrients in human physiology (Murlin 1948). During this period, lemon
juice was found to prevent scurvy, iodine to prevent goiter, and in-
completely milled rice to prevent beriberi. Despite these advances, the
most fundamental concepts about nutrition were still poorly developed at
the beginning of the 20th century. It was not until the first half of this

27


O Nutrition and Health

century that scientists identified human nutritional requirements, charac-
terized the nutritional value of proteins, and identified the amino acids,
vitamins, fatty acids, and minerals essential in the human diet (Todhunter
1976). For example, Osborne and Mendel of Yale University elucidated the
differences between complete and incomplete proteins during the first
decades of this century. Later, Rose of the University of Illinois estab-
lished which of the amino acids were essential and estimated how much of
each was required each day.

The diseases of scurvy, beriberi, rickets, and pellagra had been described
in very early writings, but their specific causes were not identified until
after 1900. In 1906, Hopkins of Cambridge University suggested that food
contained certain accessory factors necessary for prevention of these
conditions. In 1912, Funk named these factors "vitamines," later called
vitamins as more was learned about their chemical structure (Rosen 1958).

Early in the century, the dietary cause of pellagra was established by
Goldberger, a PHS physician, and fat- and water-soluble vitamins were
isolated and characterized (McCollum 1957). Also during this period,
kwashiorkor was identified as a nutritional disease and the importance of
prenatal diet on the health of newborn infants began to be appreciated
(Darby 1985). Over the next three decades, all of the vitamins were
identified, starting with the isolation of a fat-soluble substance in egg yolk
by McCollum at the University of Wisconsin, now known as vitamin A,
and continuing with the discoveries of folic acid, vitamin Br2, and other B
vitamins in the 1930's and 1940's (McCollum 1957). The essential nature of
trace elements such as selenium and zinc were finally recognized in the
1950's and 1960's (Darby 1985).

After World War II, the major focus of attention in nutrition began to shift
away from acute nutrient deficiency diseases. The advent of improved
transportation systems and home refrigeration and frozen foods expanded
the year-round availability of fresh and wholesome foods, and food for-
tification helped to increase the availability of previously scarce nutrients.
At the same time, vaccines, antibiotics, and other advances in medicine
and health prevented and controlled many of the infectious diseases that
had previously shortened the human lifespan. Thus, chronic degenerative
diseases became more important as causes of illness and death. Nutrition
scientists began to examine the relationship of modem dietary patterns and
practices to these chronic diseases-cardiovascular disease, cancer, and
diabetes, for example-that were becoming increasingly prevalent among

28


Introduction and Background cl

Americans in middle and late life, and attention shifted to the effects of
specific nutrients and dietary factors on the long. slow development of
these conditions.

Evolution of .Federal Nutrition Policy

As knowledge developed in the nutrition sciences and on the health effects
of food, and as food availability and consumption patterns became more
apparent, nutrition assumed an increasingly visible role in pubtic policy.
By 1979, the Federal Government was involved in efforts to ensure an
adequate, safe, and nutritious food supply for Americans through spon-
sorship of more than 350 programs in key areas of nutrition policy: agricul-
tural support, food safety and regulation, food fortification, food assis-
tance, nutrition services and training, food intake and nutritional status
monitoring, food and nutrition research, and food and nutrition education
(Comptroller General 1979). Some of these programs had rdots that
reached back to the turn of the century. but since World War I1 the
Government's efforts have increasingly focused on meeting the needs of
high-risk groups and on the role of-diet in health promotion and disease
prevention. Table l-3 presents a chronological listing of selected events in
the development of Federal domestic nutrition policies; the history of
Federal initiatives in the major areas of nutrition policy is reviewed below.

Table 1-3

Selected Federal Domestic Nutdtion Policy Initiatives, 1862-1988

1862


1867


1887



1889

U.S. Department of Agriculture (USDA) created. Morrill Act
establishes land grant colleges.
O&e of Education established-wi;h responsibilities for
nutrition education within public schools.
Hatch Act establishes agricultural experiment stations.
Federal research laboratory established at Staten Island.
Name is changed to the National Institute of Health in 1930.
U.S. Public Health Service Commissioned Corps authorized
for duty on communicable, nutritional, and other diseases.

1893


1906




1914

1916

USDA authorized by Congress to conduct research on
agriculture and human nutrition.
The Pure Food and Drug (Wiley) Act prohibits interstate
commerce and misbranded and adulterated foods, drinks, and
drugs. Federal Meat Inspection Act passed.
Cooperative Extension Service created as part of USDA.
USDA publishes Food for Young Children, first dietary
guidance pamphlet.

29


u Nutrition and Health

Table l-3 (continued)

1917

1921-29

1924

1927

1930

1933

1935

1936-37

1938

1939


1940


1941

1946

1947

1954

U.S. Food Administration established to supervise World Wa,
I food supply. First dietary recommendations issued by
USDA-Five Food Groups.
Maternity and Infancy Act enabled State health departments
to employ nutritionists.

Addition of iodine to salt to prevent goiter is first U.S. food
fortification program.

Food, Drug, and Insecticide Administration established. Name
is changed to Food and Drug Administration (FDA) in 1932.
USDA and Federal Emergency Relief Administration buy and
distribute surplus agricultural commodities as food relief.
Public Health Service Hygienic Laboratory designated as
National Institute of Health (later changes to National
Institutes of Health).

Agricultural Act amendments permit purchase of surplus
commodities for donation to child nutrition and school lunch
programs.

Food Distribution Program established. Social Security Act
authorizes grants to States for nutrition services to mothers
and children .

USDA conducts first Nationwide Food Consumption Survey
(NFCS).

The Food, Drug and Cosmetic (FD&C) Act includes
provisions for food standards. FDA nutrition research
program established. Social Security Act provides support for
role of nutrition in health.

Federal Surplus Commodities Corporation initiates
experimental Food Stamp Program.
National Defense Advisory Commission draws attention to
malnutrition in the United States.
President Roosevelt calls National Nutrition Conference, with
announcement of the first Recommended Dietary Allowances
by the Food and Nutrition Board. FDA promulgates standards
for enrichment of flour and bread with B-complex vitamins
and iron.

National School Lunch Program established.
Laboratories of Nutrition, Chemistry, and Pathology of the
National Institutes of Health incorporated into Experimental
Biology and Medicine Institute.
Special Milk Program established.

30


Introduction and Background 0

Table 1-3 (continued)

1955

1956

1958

1961

1%3 and 1965

1%5




1966







1966-70








1968


1968-70




I%9





1971-74

Interdepartmental Committee on Nutrition for National
Defense established (discontinued 1%7).

Title VII of the Public Health Service Act authorizes funds to
support graduate training in public health nutrition.
Food Additives Amendment to FD&C Act prohibits use of a
food additive until safety established by manufacturer.
Delaney Clause prohibits carcinogenic additives. GRAS
(Generally Recognized As Safe) list established.
President Kennedy expands the use of surplus food for needy
people at home and abroad and announces a new pilot Food
stamp Program.

Maternal and Child Health and Mental Retardation Planning
Amendments to the Social Security Act allow for an expanded
number of nutritionists in health care programs.

Food Stamp Act passed by Congress. Nationwide Food
Consumption Survey collects first data on dietary intake of
individuals.

Child Nutrition Act passed. School Breakfast Program
established. President Johnson outlines Food for Freedom
Program, the "war on hunger." Allied Health Professions
Personnel Training Act includes support for training of
dietitians.

The Department of Health, Education, and Welfare (DHEW),
which later becomes the Department of Health and Human
Services (DHHS), sponsors a National Academy of Sciences
study, Maternal Nutrition and the Course of Pregnancy, which
makes major recommendations related to the role of nutrition
in human reproduction.

U.S. Senate Select Committee on Nutrition and Human Needs
established.

DHEW sponsors Preschool and Ten-State Nutrition Surveys
that report evidence of hunger and malnutrition in poverty
groups in the United States.

President Nixon calls White House Conference on Food,
Nutrition, and Health. Secretary of Agriculture establishes the
Food and Nutrition Service to administer Federal food
assistance programs.

The National Center for Health Statistics conducts the first
National Health and Nutrition Examination Survey
(NHANES) to measure the nutritional status of the U.S.
population. This is followed by NHANES II in 1976-80,
Hispanic HANES in 1982-84, and NHANES III in 1988.

31


0 Nutrition and Health

1974

1975


1977

1978

1979

1980

1981

1984

1985

Table l-3 (continued)

1972

USDA establishes Special Supplementary Food Program for
Women, Infants, and Children (WIC). Agriculture and
Consumer Protection Act provides price supports to farmers.
Amendments to the Older Americans Act of 1%5 establish a
congregate and home-delivered meals program for older
Americans.

U.S. Senate Select Committee on Nutrition and Human Needs
issues Guidelines for a National Nutrition Policy, prepared by
the National Nutrition Consortium. Safe Drinking Water Act
passed.

National Institutes of Health establishes Nutrition
Coordinating Committee.

U.S. Senate Select Committee on Nutrition and Human Needs
issues two editions of Dietary Goals for the United States.
Food and Agricultural Act and Child Nutrition and National
School Lunch Amendments passed.

Joint Subcommittee on Human Nutrition Research established
in Office of Science and Technology Policy (in 1983 becomes
Interagency Committee on Human Nutrition Research under
joint direction of USDA and DHHS). DHEW and USDA
submit proposal to Congress for National Nutrition Monitoring
System.

DHEW establishes Department-wide Nutrition Policy Board
and issues Healthy People: The Surgeon General's Report on
Health Promotion and Disease Prevention.

USDA and DHHS jointly issue Nutrition and Your Health:
Dietary Guidelines fcr Americans. A second edition follows in
1985. DHHS issues Promoting Health/Preventing Disease:
Objectives for the Nation, which contains 17 nutrition
objectives to be achieved by the year 1990. The Surgeon
General's Workshop on Maternal and Infant Health makes
recommendations about improving nutrition for these
vulnerable groups.

DHHS and USDA issue Joint Implementation PIan for a
Comprehensive National Nutrition Monitoring System,
revised in 1987 as the Operational Plan for the National
Nutrition Monitoring System. The Select Panel for the
Promotion of Child Health, created by Public Law 95-626,
submits to Congress and the Secretary of DHHS its report,
which includes recommendations on nutrition.

The Surgeon General's Workshop on Breastfeeding and
Human Lactation develops strategies for promoting
breastfeeding.

USDA initiates Continuing Survey of Food Intakes by
Individuals. repeated in 1986.

32


Introduction and Background O

Table l-3 (continued)

1986

DHHS and USDA issue Nutrition Monitoring in the United
States, the report of the Joint Nutrition Monitoring Evaluation
Committee.

1988

DHHS publishes The Surgeon General's Report on Nutrition
and Health.

Agricultural Support. The earliest Federal nutrition policies in this area
were designed to strengthen the agricultural production system and to
ensure a consistent and adequate food supply. In 1862. the U.S. Depart-
ment of Agriculture (USDA) was created, and the Morrill Act established
land grant universities as sites for agricultural training and research. The
Hatch Act of 1887 authorized the creation of agricultural experiment
stations. As a result of these and other policies. food production increased
and farmers began to produce more food than could be consumed. Even-
tually, a system of commodity price and income supports was developed to
stabilize the economic condition of the farm sector. The Agricultural and
Consumer Protection Act of 1973 and the Food and Agriculture Act of 1977
established the basis for current agricultural support policies (Stucker and
Boehm 1978; Boehm 1979).

Food Safety and Regulation. The pure food movement of the late 1800's,
led by Dr. Harvey Wiley, chief of the Government's Bureau of Chemistry,
and popularized by the publication of Upton Sinclair's novel of 1906, The
Jungle, led Congress to pass the Pure Food and Drug Act of 1906-then
known as the Wiley Act-which prohibited interstate transport and sale of
misbranded or adulterated foods (Ziporyn 1985). This Act and the Federal
Meat Inspection Act, also passed that year, extended Federal responsibil-
ity into the arena of food safety. Significant revisions to the legislation
occurred in 1938 when the Food, Drug, and Cosmetic Act established
standards of identity and quality for certain foods, required ingredient
listings on food labels, and prohibited sales of foods that were determined
to be harmful to health. In 1958, the Food Additives Amendment to the
1938 Act shifted the burden of proof of safety to the manufacturer, required
that additives known to cause cancer in either humans or animals be
deemed unsafe (the Delaney Clause), and established the list of ingredients
in common use that were "Generally Recognized As Safe" (GRAS) for
human consumption. A 1960 Color Additives Amendment applied the
Delaney Clause to all chemical food coloring agents. Since 1969, a major
review has been under way of the safety of substances on the GRAS list
(Smith and Rulis 1981). Regulation of food safety is a shared responsibility

33


u Nutrition and Health

of several Federal agencies, primarily the USDA for plant, animal,
poultry production; the Food and Drug Administration (FDA) for all c
foods and additives; and the Environmental Protection Agency
pesticide contaminants.

The food labeling provisions of the 1906 and 1938 Acts were designe
protect consumers against fraudulent misbranding of foods, and this pc
was extended by the Fair Packaging and Labeling Act of 1%6, which cz
for accurate ingredient labeling on foods in interstate commerce (PC
1987). More recently, interest has grown in the use of food labels to edu
consumers about the nutritional quality of food and the role of nutritic
health. Regulations published in 1973 authorized voluntary nutrition la
ing and required nutrition labeling for fortified foods and those for WI
nutritional claims were made (Hutt 1981). In 1987, the FDA proposed a
policy for public health messages on food labels to permit health claim
package labels when the information is true and certain criteria are
(FDA 1987). Responsibility for regulating labeling and marketing prc
dures related to foods is shared by the USDA (meat, poultry, eggs), F
(all other foods) and, for advertising, the Federal Trade Commission (.
ter 1987).

Food Fortrjication. The onset of World War I brought new nutritic
concerns and focused attention on the need for an overall improvemer,
the availability of nutrients to the general population. The first food
tification program, instituted in 1924, was the addition of iodine to sal
prevent goiter. During the Second World War, this program was extendel
include enrichment of wheat flour with iron and the vitamins thian
niacin, and riboflavin. Also during the 1940's, milk was fortified v
vitamin D and margarine with vitamin A.

Food Assisrunce. As early as 1918, the idea of targeting food assistance
vulnerable population groups was proposed in the Children's Bureau p
lication Milk-The Indispensable Food for Children. Milk supplies 1
decreased and prices increased due to the effects of World War I, and
Children's Bureau advocated that children be given priority in allocat
milk supplies. Charitable organizations established milk stations and cc
munity kitchens to provide food supplements to the poor and to help peo
with limited income choose and prepare an adequate diet (Egan 1980

Widespread unemployment anda overty during the 1930's stimulated I
development of new Federal programs to provide food assistance to i
poor. At first, these programs focused exclusively on distribution of surp
agricultural commodities. In 1930, for example, the USDA and the Fede

34


Introduction and Background 0

Emergency Relief Administration began a distribution program as food
relief. The donation of surplus foods to child nutrition and school lunch
programs was authorized by amendments to the Agricultural Act in 1933.
The more formally organized Food Distribution Program was established
in 1935. An experimental Food Stamp Program was initiated by the Surplus
Commodities Corporation in 1939. The National School Lunch Program
was established in 1946, and the Special Milk Program was added in 1954
(U.S. Senate 1976).

In the early 1960's, as a result of surveys and assessments indicating special
needs among low-income populations (Citizens' Board 1968), the Federal
Government expanded its involvement in income support and direct deliv-
ery of food services. A pilot study in 1961 led to the Food Stamp Act of
1965, which authorized a small-scale program to meet limited needs for
food assistance. The Child Nutrition Act of 1966 established the School
Breakfast Program. Following the 1969 White House Conference on Food,
Nutrition, and Health (White House Conference 1970), eligibility and
benefits were enlarged for the Food Stamp, School Lunch, School Break-
fast, Special Milk, and Summer Food Programs; the Special Supplemental
Food Program for Women, Infants, and Children (WIG) was created;
general assistance reimbursements were increased (for the School Break-
fast and School Lunch Programs); and the Nutrition Program for the
Elderly was established through an amendment to the Older Americans
Act. From I%9 to 1977, Federal expenditures for these programs increased
from about $1.2 to $8.3 billion (U.S. Senate 1977a). By 1986, as many as 50
million Americans (the exact number is uncertain due to overlapping
benefits) were served by food assistance programs administered by the
USDA. The cost of these programs exceeded $18.8 billion in 1986 and $20
billion in 1987 (Matsumoto 1987).

Nutrition Services and Training. In the 1920's under the Federal Maternity
and Infancy Act, nutrition services were launched in nine State depart-
ments of public health. Enactment of the Social Security Act in 1935,
authorizing grants-in-aid to the States for health services for mothers and
children, was a major impetus for the further development of nutrition
services in State health agencies. By 1945, all but three States had one or
more nutrition consultant positions included in their budgets. Nutrition
services began to extend beyond maternal and child health during the late
1950's and early 1960's in response to new mental retardation, chronic
disease control, home health service, and nursing home and other ex-
tended care programs. Initiatives in primary health care, family planning,
and comprehensive health planning during the 1970's further expanded the
availability of nutrition services (Nutrition Services Project Committee

35


cl Nutrition and Health

1983), as did establishment of the Community Food and Nutrition Program
(CFN) in the 1980's to provide nutrition services to low-income popula-
tions (Office of Community Services 1987).

To ensure an adequate supply of health professionals to serve the popula-
tion, the Federal Government also supports health professions education
in primary care as well as public health practice. Since the 1940's, funds
have been available from Title V of the Social Security Act for nutrition
training of health professionals, and since 1957, various authorities under
Title VII of the Public Health Service Act have supported health profes-
sions students and curriculum development in applied nutrition, including
capitation grants to schools of public health that support traineeships for
public health nutrition students.

Food Intake and Nutrition Status Monitoring. The involvement of the
Federal Government in monitoring of food intake dates back to 1893 when
the USDA received an appropriation for this purpose (Porter 1986). The
USDA first began to collect data on the wholesale availability or "disap-
pearance" of food commodities in 1909. The subsequent annual collection
of such data has provided an important source of information on trends in
the availability of food, an indirect indicator of food use by the population
(Bunch 1987). Attempts to estimate actual food intake by the population
began in the 1930's. For example, household food purchases were exam-
ined by the USDA in 1936-37 through the first Nationwide Food Consump-
tion Survey (NFCS); such surveys have been conducted about every 10
years since, most recently in 1987-88 (USDA 1986,1987a, 1987b). Estima-
tions of the per capita nutrient content of the food supply began in the
1940's and are now reported annually (Marston and Raper 1986). The first
collections of data on the food consumption habits of individuals in
sampled households were performed by the USDA in 1%5 (NRC 1984).
Examples of food intake and availability data are given later in this chapter
in the section on dietary patterns.

Assessment of nutritional status emerged as a concern as early as 1918
when infants and children were weighed and measured during the opening
event of the Children's Year Campaign (initiated to "protect children from
the effects of war"). The impetus for this activity was the high percentage
of Selective Service rejections in World War I caused by conditions that
might have been prevented or corrected by adequate nutrition in early
childhood. The first studies of nutrition and child health were conducted by
the Children's Bureau in a mountainous section of Kentucky in 1920 and in
the industrial area of Gary, Indiana, in 1922 (Egan 1980).

36


Introduction and Background O

Much of the recent expertise in measuring human nutritional status was
developed through the work of the Interdepartmental Committee on Nutri-
tion for National Defense, which conducted nutrition surveys in more than
30 countries during the 1950's and 1960's. Attempts to evaluate the nutri-
tional status of the U.S. population began in 1956 when Congress autho-
rized the Department of Health, Education, and Welfare (DHEW) to
conduct periodic national health examination surveys; with the addition in
1971 of additional status measures, including a dietary intake component,
these surveys evolved into the National Health and Nutrition Examination
Surveys (NHANES). The first NHANES was conducted from 1971-74,
the second from 1976-80, and the Hispanic HANES from 1982-84 (DHHS/
USDA 1986). The third NHANES started in 1988. In l%8-70, in response
to increasing concern about the nutritional status of low-income popula-
tions, DHEW sponsored the Preschool (Owen et al. 1974) and Ten-State
(DHEW 1972) Nutrition Surveys and identified evidence of malnutrition in
these populations.

The dietary intake, health, and nutritional status surveys and surveillance
systems listed in Table l-4 and described above are components of the
National Nutrition Monitoring System-a complex assortment of inter-
connected activities that provide regular information about dietary intake
and nutritional status to the health of the American people and about
factors that affect diet and nutritional status (DHHS/USDA 1987). The
present system was proposed in 1978 in response to a congressional re-
quest in the 1977 Food and Agriculture Act that the Secretaries of Agri-
culture and of Health, Education, and Welfare, now Health and Human
Services (DHHS), develop a joint proposal for a comprehensive system
that would monitor the nutritional status of the American people. In 1981, a
Joint implementation Pfun (revised in 1987) committed the two Depart-
ments to close coordination of survey methods and to submission of
reports to Congress every 3 years on information gained from monitoring
activities. The National Nutrition Monitoring System includes efforts by
several Federal agencies to provide information about health and nutri-
tional status, food consumption, food composition, dietary knowledge and
attitudes, and food safety and quality.

Food and Nutrition Research. The Federal role in nutrition research began
in 1887 with the development of the forerunner of the National Institutes of
Health (NIH) as a one-room laboratory on Staten Island. In 1893, the
USDA was authorized to perform agricultural and human research. The
PHS Hygienic Laboratory developed into the first National Institute of
Health in 1930; subsequently, it was joined by other laboratories to create

37


        Table 14
National Nutrition Surveillance Activities

0
2
1.

Category          Activity

Departmenta  Agencya    Population     Timing        g.
                                                         J

Health and Nutritional
Status Measurements

National Health and
Nutrition Examination
Surveys
NHANES 1
NHANES I1
Hispanic HANES
NHANES III

DHHS      CDC/NCHS

National Health        DHHS
Interview Survey
NHIS Special Topics     DHHS
NHANES I Epidemiologic DHHS
Followup
National Survey of Family DHHS
Growth

National Maternal and    DHHS
Infant Health Survey
National Mortality Survey DHHS

CDC/NCHS

CDCR'XHS

CDC/NCHS

CDC/NCHS

CDC/NCHS              Planned 1988

CDCMCHS

Vital Statistics        DHHS      CDC/NCHS

U.S. population,
special groups

l-74 yrs       1971-74
6 mo-74 yrs     1976-80
6 mo-74 yrs     1982-84
2 mo+        1988-94

U.S.         Annual

U.S.       Selected topics
NHANES I older  1982-84, 1986,
persons       1987

Women 15-44 yrs 1976, 1983, 1987

Annual l%l-68,
1986

U.S. States,
counties, local
areas

Annual


Health and Nutritional
Status Measurements
(continued)

Coordinated State
Surveillance System

Behavioral Risk Factor
Surveillance System
Nutrition Research in
Support of Nutrition
Monitoringb

Food Consumption
Measurements

Nationwide Food
Consumption Survey
(NFCS)
Continuing Survey of
Food Intakes by
Individuals (CSFII)
1985 and 1986

1989 and beyond

NHANES

DHHS

CDCKHPE  Pregnant women, Continuous
        children

CDCKHPE   Adults

Continuous

DHHS
USDA

NIH       Varies      Ongoing
ARS
CDCKHPE
FDA

USDA      HNIS

U.S., low-income Every 10 years,
sample       current 1987-88

USDA      HNIS

DHHS

CDCINCHS

Women 19-50,   Annual
their children,
men, low-income
sample               zi
U.S. population,  Annual (planned)    E
low-income                         a
sample, other            !?
U.S. population  1971-74, 1976-80,
         1982-84, 1988-94  g
                 s
         ii


Table 14 (continued)

Food Consumption     Total Diet Study
Measurements (continued)
               Vitamin/Mineral
            Supplement Adverse
                Reactions

Food Composition
Measurements

Nutrient Data Bank

Nutrient Composition
Laboratory
Food Labeling and
Package Survey
Total Diet Study
Fiber, Carotenoid, and
Vitamin A Comp. Studies;
Taurine and Biotin Comp.
Studies

Dietary Knowledge     Health and Diet Survey
and Attitude Assessment
            Survey of Infant Feeding
                Practices

Survey of Weight-Loss
Practices

Cholesterol Awareness
Survey

DHHS

FDA

DHHS      FDA

USDA

USDA

DHHS

DHHS

DHHS

DHHS

DHHS

DHHS

DHHS

HNIS

ARS

FDA

FDA

NIH/NCI

NIHI
NIDDK

FDA

FDA

FDA
NIHI
NHLBI

NIHI
NHLBI
+ FDA

Specific age-sex Annual
groups
U.S.         Continuous



          Continuous


          Continuous

Annual and
biennial parts
Annual
Ongoing

Ongoing

U.S. adults     .18-22 mo intervals

Pregnant women  1988 or 1989


U.S. adults     1987 or 1988



Physicians      1986

Adults


e

Dietary Knowledge and
Attitude Assessment
(continued)

Nursing and Dietitian
Survey

NHIS Special Topics
Health Promotion/
Disease Prevention

.

VitMn Supplement
Cancer Control

Food Supp!y
-

CSFII Followup
(Consumer Perceptions
Survey)
Physician Knowledge
Survey on Hypertension
Cancer Prevention
Awareness Program
Demand Studies

DHHS      NIH/
        NHLBI

DHHS     CDC/NCHS   U.S. adults

        + NIH/NCI
USDA/DHHS HNIS
        FSIS
         FDA

DHHS      NIH/NHLBI

DHHS      NIH/NCI

USDA      ERS

Nurses, dietitians 1986, 1987

1985

           1986

           1987
U 3. population  Planned 1989-%



Physicians      1978-88


U.S. adults    1984 + ongoing

U.S. population Continuous

Determinations

aARS = Agricuftural Research Service, CDC = Centers for Disease Control, CHPE = Center for Health Promotion and Education, DHHS =
Department of Health and Human Services, ERS = Economic Research Service, FDA = Food and Drug Administration, FSIS = Food Safety
and Inspection Service, HNIS = Human Nutrition information Service, NCHS = National Center for Health Statistics, NCI = National Cancer
Institute, NHIS = National Health Interview Survey, NHLBI = National Heart, Lung, and Blood Institute, NIDDK = National Institute of Diabetes
and Digestive and Kidney Diseases, NIH = National Institutes of Health, USDA = U.S. Department of Agriculture.
blncludes research on nutritional status assessment and requirements throughout the life cycle. The nutritional status research focuses on (1)
indices of nutritional status, (2) micromethods to measure nutrient concentrations in various tissues and plasma, and (3) methods that improve
accuracy of dietary intake data.

Source: U.S. Department of Health and Human Services and U.S. Department of Agriculture 1987.


n

u Nutrition and Health

the present research enterprise of NIH (Simopoulos 1986). In 1975, the
NIH Nutrition Coordinating Committee was established to address NIH
nutrition issues that span the goals and purposes of 12 Institutes, 2 Divi-
sions, and 2 Centers within the agency. The FDA began conducting nutri-
tion research in 1938. By 1976, Federal expenditures for nutrition research
and research training exceeded $73 million (U.S. Senate 1976). The amount
was reported as nearly $200 million by 1979 (JSHNR 1980) and $270 million
in 1984, of which nearly $200 million represented research supported by
NIH (ICHNR 1986; NIH 1987). In 1987, NIH expended a total of $261
million, reinforcing its longstanding position as the major Federal agency in
biomedical and behavioral nutrition research and training support. This
nutrition research encompasses a broad range of topics, including health
maintenance, human development throughout the life cycle, disease pre-
vention, and disease treatment.

The Interagency Committee on Human Nutrition Research (ICHNR) was
established by the Secretaries of DHHS and USDA to succeed the Joint
Subcommittee on Human Nutrition Research that operated out of the
White House Office of Science and Technology Policy to coordinate all
Federal nutrition research activities. The ICHNR produced a 5-year plan
for human nutrition research that reviewed the research activities of eight
Federal agencies, listed research priorities, and identified six areas for
expanded research investigation: nutritional requirements at various
stages of the life cycle, nutrition interactions and bioavailability, nutrition
and chronic diseases, energy regulation and eating disorders, nutrition
monitoring, and nutrition education methodology (ICHNR 1986).

Dietary Guidance and Nutrition Education. The Federal Government has
supported efforts to teach the public about nutrition since 1867 when the
Office of Education was established with responsibility for nutrition educa-
tion within the public schools. The Children's Bureau of the Department of
Labor published Prenatal Care in 1913 and Znfant Care in 1914 to provide
dietary guidance to mothers. These books have been in publication ever
since and are all-time best sellers of the U.S. Government Printing Offtce.

The USDA also had an early role and published its first food selection
guide, designed to help parents meet the nutritional needs of young chil-
dren, in 1916 (Hunt 1916). Since that time, federally supported dietary
guidance materials have been issued and revised regularly to meet the
needs of specific target audiences and to reflect emerging knowledge of
nutritional science. A list of Federal dietary guidance publications for the
general public since 1917 is presented in Table l-5.

42


e

                 Table l-5
Federal Dietary Recommendations for the General Public, 1917-1988

Recommendationa

Year   Agencyb

Publication

     Maintain Include
      Ideal    Starch            Limit
     Body    and   Limit Limit Choles- Limit   Limit
Variety  Weight   Fiber  Sugar   Fat    terol    Salt   Alcohol

1917 USDA

1942 USDA

1943 USDA


1946 USDA


1946 USDA

1958 USDA

1977 U.S. Senate
1979 USDA

1979 DHEW

1979 DHEWINCI

What the Body Needs-
Five Food Groups
Food for Freedom-
Daily Eight
National Wartime Nutrition
Guide-Basic Seven
National Food Guide-
Basic Seven
Food for Growth-
Four Food Groups
Food for Fitness-
Four Food Groups
Dietary Goats for the U.S.
Building a Better Diet-
Five Food Groups
Healthy People: The Surgeon General's
Report on Health Promotion and
Disease Prevention
Statement on Diet, Nutrition,
and Cancer--Prudent
Interim Principles

+


+

+

      + * *


       +            *



       +            *



       +            *



       +


       +


+       +      +     +      +      +
+       +      +     +      +      +      +


+       +      +     +      +      +      t

-I-       t           +                  +


Year   Agencyb

Publication

                           0
                                                   z
                                            5
Table l-5 (continued)                      g
                                  Ei
                      Recommendationa              5
           Maintain Include
            Ideal    Starch             Limit       i

          Body and   Limit Limit Choles- Limit        2

    Variety  Weight   Fiber  Sugar   Fat    terol   salt  Limit 5
                                           Alcohol

   1980 USDA/DHHS  Dietary Guidelines for Americans        +       +       +      +     +      +      +      +
   1980 DHHS      National 1990 Nutrition Objectives        +       +       +      +     +      +      +      +
   I984 DHHS/NHLBI Recommendations for Control                  +                   +            +      +

% 1985 USDA/DHHS   of High Blood Pressure
              Dietary Guidelines for Americans,        +       +       +      +     +      +      +      +
                  2nd edition
   I986 DHHS/NCI   Cancer Control Nutrition Objectives              +       +           +                  +
                  for the Nation: 1985-2000
   1987 DHHS/NHLBI National Cholesterol Education         +       +       +           +      +            +
               Program Guidelines
   1988 DHHS/NCI    Dietary Guidelines for Cancer           +       +       +           +            +      +
                   Prevention

`!7ecommended for inclusion in the daily diet, as opposed to subsequent recommendations to limit intake.
aOther recommendations include: increased consumption of foods containing vitamins and minerals (USDA 1917-l 958; NCI 1988) increased
physical activity (USDA/DHHS 18881985; DHHS 1980). and reduced intake of salt-cured or smoked foods (NC1 1988).
bUSDA = U.S. Department of Agriculture, U.S. Senate = U.S. Senate Select Committee on Nutrition and Human Needs, DHEW = Department
of Health, Education, and Welfare, DHHS = Department of Health and Human Services, NCI = National Cancer Instiiute. NHLBI = National
Heart, Lung, and Blood Institute.


Introduction and Background O

The earliest federally sponsored guidelines advised the public to consume
portions from a variety of food groups every day to obtain sufficient energy
and to avoid nutritional deficiencies. As more was learned about nutrients
essential in the diet, recommendations began to emphasize consumption of
foods containing vitamins, minerals, and other "protective" dietary com-
ponents (Hertzler and Anderson 1974). In response to the economic crisis
of the 1930's, the USDA began to develop meal plans for consumers at
different levels of income to address issues of cost (Haughton, Gussow,
and Dodds 1987).

The first Recommended Dietary Allowances (RDA's) for intake of energy
and eight nutrients were developed by the National Research Council and
adopted at the wartime National Nutrition Conference in 1941 (Roberts
1958). RDA's have been published periodically since; the most recent
(ninth) edition appeared in 1980 (NRC 1980). Its recommendations are
reviewed later in this chapter. Also in 1941, the USDA, in cooperation with
the Offtce of Education and the PHS, published the first Federal guide to
incorporate information on specific vitamins and minerals and the first to
use the term "enriched." Meal plans and dietary guidelines published since
the 1940's have been designed increasingly to translate the RDA's into
terms usable by consumers (Hertzler and Anderson 1974). The USDA's
1958 Food for Fitness-A Daily Food Guide, written in terms of four food
groups, was the first to promote intake of specific nutrients-alcium,
vitamin A, and vitamin C-that were commonly consumed in amounts
substantially below RDA levels (Haughton, Gussow. and Dodds 1987).

Typically, an adequate diet has been defined as providing the basic food
groups that would contain amounts of essential nutrients-protein, vi-
tamins, and minerals-sufficient to prevent deficiency diseases. In the
mid-1970's, however, the focus of national policy objectives expanded to
encompass the role of overconsumption of fat, cholesterol, salt, sugar, and
alcohol as dietary factors associated with chronic disease. The increasing
scientific interest in these relationships led the U.S. Senate to hold hear-
ings on diet and health from 1973 through 1977 (U.S. Senate 1977a).
Expanding knowledge of the role of diet in health maintenance also led to
the development in 1975 of a DHEW Policy Statement on Health Aspects
of Nutrition (U.S. Senate 1976). Thus, dietary adequacy began to include
consideration of the most reasonable proportions of dietary factors for
prevention of chronic-rather than deficiency--diseases.

This new perspective was reflected in the two editions of the 1977 report
Dietary Goals for the United States, produced by the Senate Select Com-
mittee on Nutrition and Human Needs (U.S. Senate 1977b. 1977~). These


u Nutrition and Health

reports recommended significant changes in average dietary intake pat-
terns to improve protection against the principal chronic diseases. To
accomplish this goal, they established quantitative targets for consumption
of complex carbohydrates and naturally occurring sugars (greater than 48
percent of energy), refined and processed sugars (10 percent of energy),
total fats (less than 30 percent of energy), saturated fat (less than 10 percent
of energy), cholesterol (less than 300 mglday), and salt (less than 5 g/day)
(U.S. Senate 1977~).

These principles, although not the quantitative targets, were supported and
expanded in the 1979 report Healthy People: The Surgeon General's
Report on Health Promotion and Disease Prevention (DHEW 1979) and by
the 1980 publication Nutrition and Your Health: Dietary Guidelines for
Americans, jointly issued and revised in 1985 by the Departments of
Agriculture and of Health and Human Services (USDAIDHHS 1985). The
Guidelines recommend:

o Eat a variety of foods.
o Maintain desirable weight.
o Avoid too much fat, saturated fat, and cholesterol.
o Eat foods with adequate starch and fiber.
o Avoid too much sugar.
o Avoid too much sodium.
o If you drink alcoholic beverages, do so in moderation.

This approach reflects the increase in interest in the relation between
nutrition and prevention of chronic diseases, a development that has
shaped and mandated Federal nutrition education activities of the past
decade (see Table l-4) and is the principal focus of the discussion, conclu-
sions, and recommendations of this Report.

Scientific Background

Human Nutritional Requirements

Essential nutrients must be obtained from the diet in the proper amounts
and proportions to maintain good health and to prevent deficiency dis-
eases. A deficiency of an essential nutrient causes signs and symptoms that
can be prevented or cured by an increased intake of the nutrient. Such
deficiencies may be due to inadequate dietary intake, or they may be

46


Introduction and Background 0

induced by either inherited or acquired inabilities to absorb, transport,
store, or metabolize nutrients or by excessive losses of nutrients from the
body (for example, from vomiting, bleeding, or diarrhea).

Just as a deficiency of a nutrient can cause disease, too much of a nutrient
can also lead to disease. For example, as discussed throughout this Report,
the excessive consumption of energy, fat (especially saturated fat), and
alcohol have been associated with the development of specific chronic
disease conditions in some individuals. Excessive intake of some vitamins
and most of the minerals also has been shown to result in either acute or
long-term disorders. For most nutrients, there appears to be a safe and
adequate range of dietary intake that satisfies nutritional requirements but
does not cause untoward symptoms. This concept is illustrated in Figure
l-1. Ideally, the diet should contain energy and all of the essential nutrients
in amounts that fall within these ranges of intake.

I ( )I Y'o

                        .:.:.:.:.:.:.:.:.:.:.:.~..:.~.~:.:.~:.~.~: .:
                        .........................................
                      . .
                     ........ . .          ......................... , . .
                       . . ..:.1:.:.~:.:.:.:.:.:.:.:.: .:.
                        . . . . . . ...... . . . . . . ... . ...... . . . . . . ... . ............................
                      .....................................
                     ......................................
                      ..........................................................................
C                    :.:2..~:.:.~:.~:.:.:.:.:.:.:.~..~:.:.:.~:.:.:.:.:.:.:.:.:.:.: .
                     ......................................
.z                ..............................................................................
                      . ..... . . . . . . . . . . . ...... . ... . . . . . . . .... . . . . . . . . . . . . ...... . . . . . . . . . . ......
                      ......................................
                     . . .....................................
5                     ....................................
                      .....................................
                      .................................... . .
C                   :.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.~:.:.:.:.:.~:.:.~.~.:.~~ ...
                      .....................................
3                 .:::::::~::::::::~~::::::::::::::::::::::::::~::::~.::::~:::
L                    . ........................................
                      . . . .... . . . . . . ... . . ..... .................................................
                      .....................................
                      . .....................................
                      ....................................
                      .................................... . .
                      .....................................
                     .....................................
                      ..................................... .
                      .......................................
                      . . . . . . . . .... . . . . . .               .
                           ......................................................
                      .....................................
              .................................................
                        . . . . . . . . . .               .
                           .......................................................
                   ... . .
                   ... ......
                      ...... . ... . . . . ............................................................
                      . . . . . . -. . .
                        . . . .
                         . . . .... ... ..... . . .
                           ........ .
                        . . . . . . .   ..................................................
                             . . . . ...... . . . . . . .... ...... . . . ... .... . . ........ .
                     .........  ............................................................
                      ..................................... .
                     ....................................
                     .:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:        . .
                                 .............................
                                  ...............
                     ~:.:.~:.:.~..:.:.:.:.:.:.:.:.:.:.:.~:.:.~:.:.:.~:.:.~..:.:.:.: .:

*   Concrnkltion or intake of nutrient -

Figure l-l. Dependence of biologic function or tissue concentration on in-
     take ol a nutrient. For nutrients and energy sources, there is a
    range of intake that confers optiil physiologic function. Below
    thII range, deficiincies can cause dii or death. Excecrsive
     intake also can lead to increasiing symptoms of toxkity. The op-
     timal range varies for each nutrient and is affected by many
      indiiidual and environmental factors.

Source: Merlz, W. 1981. The essential trace elements. Science 213:1332-38. Copy-
   right 1981 by the American Association for the Advancement of Science, re-
    printed with permission.

47


u Nutrition and Health

Recommended Dietary Allowances

The need to establish goals for good nutrition in the United States was
recognized in the 1930's and led to the establishment in 1940 of the
Committee on Food and Nutrition, now called the Food and Nutrition
Board, of the National Research Council, National Academy of Sciences.
The Committee's initial purpose was to make sure that the population was
adequately nourished during World War II, and one of its early functions
was to recommend quantities of nutrients that should be provided to the
Armed Forces and the general population. These recommendations led to
the development of goals for intake of nine specific nutrients that would
meet the known nutritional requirements of men, women, and children of
varying ages. These first RDA's were adopted in 1941 (Roberts 1958), and
they have been published at 5- to lo-year intervals since 1943. Although the
original purpose of the RDA's was to promote nutritional health during
wartime, their purpose has expanded over the years to include use for
development of standards for food assistance programs, food labels, and
evaluation of dietary adequacies.

Because research on human nutritional requirements is often incomplete
or inconsistent, and because of variability in individual nutrient require-
ments, the RDA's represent an estimated, rather than an absolute, stan-
dard of dietary adequacy, and they are revised periodically to reflect
current scientific evaluation of the available nutrition research. The most
recent revision was published in 1980 and is presented in Table l-6 (NRC
1980). The RDA's are defined as ". . . the levels of intake of essential
nutrients considered, in the judgment of the Committee on Dietary Allow-
ances of the Food and Nutrition Board on the basis of available scientific
knowledge, to be adequate to meet the known nutritional needs of prac-
tically all healthy persons." Thus, each RDA is deliberately set higher than
the.actual requirement for that nutrient in most individuals.

Specific RDA's have been established for protein, 10 vitamins, and 6
minerals; they are presented in categories that vary according to body size.
gender, and energy consumption (NRC 1980). RDA's are usually higher for
males than for females, except for women who are pregnant or lactating.
For 12 additional nutrients, research has been too limited to establish
specific RDA's and the Food and Nutrition Board has proposed ranges of
daily intake that are considered "safe and adequate." These are presented
in Table l-7. The RDA's are designed to exceed the nutrient requirements
of most individuals, but the allowances for energy are designed to reflect
average needs for people of different heights and weights, ages, and activi-
ty levels.

48


                               Table l-6
              Food and Nutrition Board, National Academy of Sciences-
       National Research Council Recommended Daily Dietary Allowances,a Revised 1960
     Designed for the maintenance of good nutrition of practically all healthy people in the U.S.A.

                                              Fat-Soluble Vitamins
         Age       Weight        Height       Protein    Vitamin A    Vitamin D     Vitamin E
        (years)    (kg)    (lb)    (cm)    (in)     w     ha REJb     (CLkT)C     (mg a-TE)d


   Infants   0.0-0.5                  60     24    kgx2.2       420        IO           3
          0.5-I .o   x   s      71     28    kgx2.0       400        IO           4
   Children    1-3      13      29      90     35       23        400        IO          5
                   20      44     112     44       30        500        IO           6
    7%      28      62     132     52       34        700        IO           7
   Males     11-14      45      99     157     62       45        loo0        IO          8
%          15-18      66      145     176     69       56        looo        IO          IO
           B-22            154     177     70               loo0        7.5         10
          23-50   z     154     178      i:        loo0         5          IO
           51+      70     154     178  ::       56        loo0         5          IO    $
   Females   11-14      46      101     157     62       46        800        IO           8   1
           15-18      55     120     163     64       46        800        IO
           19-22     55     120     163     64       44        800        7.5    t         0
                                                      g.
          23-50      55      120     163             44        800         5           8         1
           51+      55      120     163  iii       44        800         5           8     B
    Pregnant                                     +30       +200        +5         +2         e
   Lactating                                +20       +400        +5         +3         m
                                                                    R
  aThe allowances are intended to provide for individual variations among most normal persons as they live in the United States under usual en-  9
   vironmental stresses. Diets should be based on a variety of common foods to provide other nutrients for which human requirements have been
    less well defined.                                               s
   Wetinol equivalents; 1 RE = 1 kg retinol or 6 pg $ carotene.
   CAs cholecalciferol; 10 pg cholecalciferol = 4000 IU of vitamin D.
   da-tocopherol equivalents: 1 mg d-a tocopherol = 1 a-TE.


                        Table l-6 (continued)                    0
                                     2
                           Water-Soluble Vitamins
        Age Weir&                                      s:
                     Height   Vitamin C Thiamin Riboflavin  Niacin  Vitamin B, Folacinr Vitamin B,,
        (years) (kg) (lb) (cm) (in)   b-fg)    (mg)    (mg)   (mg NEP   (mg)    h3)    (Ia)     iz
                                                           E
    infants   0.0-0.5 6 13                                                                           0.
                        60 24     35      0.3      0.4      6       0.3      30     0.5g      X
          0.5-1.0 9 20   71 28     35      0.5      0.6      8       0.6      45      1.5     i!
   Children    l-3       29   90 35     45      0.7      0.8      9       0.9      loo    2.0 g
       :i   44 II2 44      45      0.9      1.0      II       1.3      200      2.5
    7% 28   62 132 52     45       1.2      1.4      I6       1.6      300     3.0
    Males     II-14 45   99 I57 62     50       I.4      1.6     18              400      3.0
          15-18 66 I45 176 69     60       I.4      1.7     I8   :*:      400      3.0
           19-22  70 154 177 70      60      1.5      1.7     19    212      400      3.0

3          23-50 70 154 178 70     60       I.4      1.6      18       2.2
           51+   70 154 I78 70     60       1.2      I.4     16       2.2   z   :-I
   Females   II-14 46 IO1 157 62     50       I.1      1.3     I5       1.8      400    3:o
            15-18   55 120 163 64      60      I.1      1.3     14       2.0      400      3.0
           19-22   55 120 163 64             I.1      1.3      14       2.0             3.0
          23-50 55 I20 163 64  2      1.0      1.2     I3      iti      3.0
            51+   55 120 163 64     60       1.0      1.2     I3   El     400      3.0
    Pregnant                       +20     +0.4     + 0.3     +2      + 0.6     +400     +1.0
    Lactating                      +40     +0.5     +0.5     +5      +0.5     +100    +1.0
  eNiacin equivalent; 1 NE = 1 mg of niacin or 60 mg of dietary tryptophan.
  f The folacin allowances refer to dietary sources as determined by Lactobacillus casei assay after treatment with enzymes (conjugates) to make
   polyglutamyl forms of the vitamin available to the test organism.
  @Ihe recommended dietary allowance for vitamin B12 in infants is based on average concentration of the vitamin in human milk. The allowances
  after weaning are based on energy intake (as recommended by the American Academy of Pediatrics) and consideration of other factors, such
    as intestinal absorption.