Prediction of iron absorption blood donors13 Philip and

J Garrv, Toby

Sharon

Iron stores were assessed who donated five units

women over

unit)

1 y. The

time

average (range

8-30

Iron

mean

between wk).

± 3.88 mg/kg mg/kg by the based

M Koehler,

Dorothy

age was

successive

blood

Steady-state

on biochemical were

equations healthy

becoming

(±SD)

in 27 postmenopausal of blood (-485 mL/

iron

67.7

± 4.0 y and

donations

stores

was

at entrance

the

10 wk

were

10.59

body wt (1 ± SD) and declined to 1 .03 ± 3.20 fifth donation. Determination of iron stores was

intakes

oped which

Kathleen

on iron status R Pathak,

of female

Richard

N Baumgartner,

L Simon

ABSTRACT

healthy

J Wayne,

based

measures 23.3

that can postmenopausal

iron

deficient.

of iron

10. 1 mg/d.

±

be

status

From

at each these

donation.

data

ability

women

ofelderly

to become

data

that

their

health

from

the

blood

In a recent

for

in the

(8).

Considering

y ofage,

we examined

healthy

Health

This

study

who

in iron

donated

also

showed

that

iron

ofdietary

iron

dietary

losses;

iron

to replace

iron

by blood donation may explain this Cook et al (1 1) recently conducted

phenomenon. iron-absorption

young

diets

KEY

WORDS

Iron

blood

nations,

Absorption,

elderly

women,

blood

do-

donors

of age and older, but evaluated. Blood-donor some accept permission)

donors, physician

Some

tinctions.

without

addition,

age-related centers donors whereas

literature

limited

generally

>

that

elderly

from

people

in acute

autologous

morbidity

people

65 y

65 y old on a limited basis others make no age-related

increase

with

excluded

donation criteria are being rediffer in their approach to elderly

suggests

a significant

experience

shown

have

programs

donate

programs

by individuals

over a 2-wk self-selected

bioavailability, absorption

was compared with a wide

losses

due

absorption replace

stating

that

“the

on

nonheme-iron

has

our

finding

sorption

influence

in a normal

of dietary

diet

by meals

absorption.”

that

elderly

as iron

stores

women were

This

studies

between spectrum

steadily

in

shown

individuals of predicted to enstudies, dietary

the percent composition, and

have

report

lost

ofnonheme iron. iron absorption

inhibitors that

of

iron

as well as diets

was the major factor determining of nonheme iron given normal dietary

In

even

intestinal

the bioavailability were noted when

period diets

was

bioavailability

hance Cook

is diluted

( 1 , 2).

reactions

donation

donations

can

(with dis-

or enhance differences

was

there

increased as iron of dietary iron

to completely

self-selected

et five

intake

and those consuming a diet known nonheme-iron absorption. From these and related et al (1 1) concluded that iron status, rather than

iron

Blood-donor

increase iron

consuming

either to inhibit No significant measured consuming

Introduction

blood

adults

in 27 of blood

however,

iron absorption bioavailability

to effectively supplemental

status

five units

69 1-8.

and

are

I 8 million

calculated by the method ofCook ± 255 mg to 67 ± 210 mg after

obligatory

absorption

inability

rate

there

this represents

to blood donation even though stores were depleted. Decreased dietary

States that

successful blood donors depends primarily on initial iron stores, iron intake, and frequency ofdonation. Women with low steadystate iron stores may be able to donate only two times per year without becoming iron deficient. Am J C/in Nutr l992;56:

or an

Statistics

United

changes

women

Iron stores, from 697

to replace

insufficient

Center

65 y old

donors.

1 y (9). dropped

sufficient

65-84

report

postmenopausal

donations.

>

to excellent

as good Americans

potential

National

of people

68.3%

26 million

over al (10),

we devel-

used to predict the frequency at women can donate blood without

The

Recent show

enhancers

no overall

effect

is consistent

increased

their

with iron

ab-

depleted.

from individuals at very advanced ages (3, 4). Because the elderly population has relatively high iron stores, they are good candidates for publication

regular blood donation (5, 6). In a recent landmark detailing the only extensive sociologic research on

blood donations, Piliavin and Callero (7) emphasize the for increased donation by elderly people: “Elderly and late dle-aged

people

pool,

undoubtedly

anyone

over

have been under as a result

65. The great

age today

are healthy

as donors

such

engage

in high

Am J C/in Nuir

majority

and vigorous

as having risk

represented

ofthe

activities

1992:56:691-8.

more

free than Printed

in the blood

previous

practice

ofthosejust and may time

and

do younger in USA.

need middonor

of deferring

past retirement provide being

advantages less likely

to

people.” © 1992 American

Society

Downloaded from https://academic.oup.com/ajcn/article-abstract/56/4/691/4715573 by St Bartholomew's & the Royal London School of Medicine and Denistry user on 29 August 2018

I From the Departments of Pathology, Biochemistry, and Family, Community, and Emergency Medicine, University ofNew Mexico School of Medicine, Albuquerque, NM; and the United Blood Services, Albuquerque, NM. 2 Supported by grants HL36 158, AG02049, and GCRC DRR, 5M0 100997-13,14 from the United States Public Health Service. 3 Address reprint requests to Pi Garry, UNM School of Medicine, Room 215 Surge Building, 2701 Frontier Place NE, Albuquerque, NM 87131. Received January 2, 1992. Accepted for publication May 1 1, 1992.

for Clinical

Nutrition

691

692

GARRY In another

recent

report

critically analyzed iron requirements studies.

They

found

a linear

as iron stores decreased, when iron stores were -300

mg.

Their

of long-term

Hallberg

available data in menstruating

present

data why

and

may

successful

become

blood

help

the

will

upper

as regular why

without iron

limit

donors,

we

women

becoming

become

iron

deficient

will

deficient

after

measurements dietary

food

several

Subjects

reported

and

Study

methods

subjects

were

participants

in a study

on blood

men and groups.

The donor group consisted of 58 men and 52 women who donated one unit ofblood (485 mL) every 8-10 wk. The control group was examined at the same frequency as were the donors but they did not donate blood. A blood sample (7 mL) was obtained from the donors and control subjects at each visit. This report presents data on the female subjects because ofthe higher incidence

of iron

men

five blood

after

the

female

study

dose

and

recorded

Estimates

ofbody

iron was

separately

of New

Research and

ad-

Center.

portion

size

sources of iron ( 15- 17). A tables was adapted from

to calculate

self-supplementation

was

physical

University

Clinical

of consumption

used

and

from

from

intake

reported

(16,

1 7). Iron

by frequency

dietary

iron

and

intake.

iron

donors

and

female

deficiency

have

donors

had

to have

made met

noted

donations.

in women

compared

To be included

in this

completed

5 donations.

these

criteria

the

first

and

were

with of the

of the

included

in our

52

anal-

is divided

a deficit

for iron

stores

of iron

that

accumulate. In this

Informed

consent

Laboratory

was

by the Human ofNew Mexico

obtained

from

each

Research Review School of Medicine.

measurements

Hemoglobin

(Hb)

determined

calculations

bin method. Plasma iron and total-iron-binding were measured by an automated colorimetric

capacity (TIBC) method using sul-

fonated

bathophenanthroline

saturation percent

was calculated by expressing the plasma of the TIBC. Plasma ferritin determinations

formed

with

Abbott

Laboratories,

a two-site

Iron status for long-term serum

control The

indices (iron, reproducibility (Lyphocheck,

average

CVs

3 15) and 40.6 zmol/L,

measurements for concentrations

over

for ferritin (n = 77), and

enzyme

20 ig/L,

(14).

to estimate

immunoassay

iron were

women and The

and

for

iron

Laboratories,

measurements

1 y were 4.8% (n = 367) of 54.5 and 40.8 amol/L

respectively.

over (n = 81)

6 mo for

1 y were

and 5.4% (n = 335) TIBC. The average 6.3%

Hb determinations

stores

ferritin

for

=

values

the amount iron

by the

iron

amount

stores

method

(400

of Cook

Appendix

stores

that

the

-80

ofthe must

point

The

index

in their

Level

3. Positive For

12 .tg/L).

for

saturation

Hb)

level

difference 2 algorithm

for either

level

1

on the plasma

approximated before

deficit Hb

Hb

0 to 5 was

assigned

1 25 g/L

X index

normal

from

de-

1 g/L

criteria

occur

for

ranging

A. These

saturation




Hb

without not

measures separate

a transferrin

16% and 12 g/L, used to define level

one-fifth mg)

values

with