890
THOMPSON AND LENGEMANN
techniques and general applicability of such work.
In addition, the
representativeness of the samples from the field studies is questionable, and the conditions inherent in metabolic-ward studies do not
reflect normal behavior for most individuals.
In an attempt to examine the nature of individual variations as
well as to determine the feasibility of this approach under normal
conditions, a urine/diet study was conducted during March 1964.
Fourteen volunteers (7 males and 7 females) ranging in age from 21 to
33 years were placed on balanced diets for 17 days. The content of
each day’s diet was the same throughout the entire 17-day period. All
diets were made up in advance from the same coded batches of raw
products. They were prepared in frozen-dinner form and distributed
to the volunteers on a prescribed schedule. The volunteers followed
their normal daily work or recreational patterns, consuming the
meals on their normal schedules. Daily urinary collections were
started after six days and were subdivided to permit comparison of
first morning specimens with “rest-of-day” or total 24-hr samples.
Alternate-day samples were analyzed for
each person to measure
variations over time and between subjects. All volunteers completed
the study and adheredstrictly to the schedule.
The average Sr level in the diet was 24.8 pe per gram of calcium
for the male diet and 22.3 pc per gram of calcium for the female diet.
Diet-calcium intakes were approximately 1.0 g in eachinstance.
Results of the analyses indicated an overall OR,..../gie, Of 0.97 +
0.08 (1.07 for females and 0.87 for males). This compares with the
ORurine /diet Of
0.82
for
young
adults determined in the Samachson
study.’> The Similarity of results would seem to indicate that urinary
%Sr/calcium values can be used to predict dietary levels. However,
Table 4— RELATIVE DISTRIBUTION OF ORurine/diet VALUES,
DIETARY STUDY, 1964
OR urine/diet
Percent
of observations
.
ORurine/diet
<0.50
0.50 to 0.74
1.9
23.1
1.25 to 1.49
1.50 to 1.74
3.8
1.9
1.00 to 1.24
17.3
>2,.00
3.8
0.75 to 0.99
44.2
1.74 to 1.99
Percent
/
of observations
3.8
this would not apply to estimates of individual persons since the range
of daily OR,.ine/diep Values observed in this study extended from 0.49 to
2.95. Although the difference between high and low values seems
rather large, the OR values were concentrated in the range between
0,50 and 1.24 (see Table 4). Since 85% of the OR values were observed
within this range, this procedure would seem to be Suitable for esti-