conspectus of researchon copper metabolism and requirements

2034 KARL E. MASON
vegetarian type of diet, differences in cop
per content of soil and/or water, contami
nation through common use of tinned-cop
per cooking utensils, or some combination
of these factors can provide an explanation
is speculative. The estimated minimal re
quirement of 2.0 mg is based upon statisti
cal analyses of the balance data ( 154). The
data of De ( 154) clearly support observa
tions of others (100, 451, 452) that as di
etary copper intake increases there is an
increase in the amount retained, up to an
intake of about 8 mg/day. It should also
be noted that in the diets used by Butler
and Daniel (84) a mineral and baking
powder mix was added, providing at two
meals a total of 2.37 mg of copper per day,
thus explaining the high levels of intake
and output. However, there is no valid
basis for their concluding statement that
"a copper allowance of 4.5 to 5.0 mg is
needed to cover the requirements of all
healthy young women, depending on cli
matic conditions."
The study of Kyer and Bethel (431) is
the only known report on copper require
ments of the pregnant woman. In view of a
2- to 3-fold increase in serum ceruloplasmin
during gestation, presumably attained
through calls upon storage depots of the
liver and other organs and tissues, an in
crease in daily intake of copper to replace
this tissue depletion would be anticipated.
In this study a healthy young woman was
maintained during the last 3 months of her
pregnancy and for 2 weeks after delivery
on a uniform diet providing a daily intake
of about 2.2 mg of copper. At this level of
intake she was able to meet normal needs
for pregnancy and early lactation.
Balance studies carried out during the
past 14 years, represented by the last eight
listed in table 3, indicate that levels less
than 2 mg and sometimes not greatly in
excess of 1 mg may maintain positive cop
per balance. Such conclusions are in gen
eral accord with information provided by
parenteral nutrition studies, as discussed
in the following section. Nevertheless, it is
important to bear in mind that at these
low levels of intake there is, as yet, no
means of determining to what extent body
mechanisms of copper homeostasis may in
volve decreases of copper stored in the
liver and other tissues of the body.
Total parenteral nutrition. The advent of
total parenteral nutrition (hyperalimentation)
and its application to problems of
post-surgical nutrition and gastrointestinal
disorders has added greatly to knowledge
of copper utilization and requirements. A
number of observations which have par
ticular relevance to adult human require
ments for copper warrant consideration at
this point.
Shils et al. (712) report the case of an
adult male, with bowel resected from the
third part of the duodenum to the ascend
ing colon, who was maintained in good
nutritional status solely on parenteral feed
ing for many months. The basic parenteral
fluid was essentially devoid of copper, but
was supplemented with various trace ele
ments which included 0.40 mg copper/day.
Bergstrom et al. (45) describe a 43-year
old woman suffering from epilepsy and
cerebral damage due to CO^. intoxication
from a fire, who was maintained for 7
months and 13 days on total parenteral
nutrition, with an estimated daily intake
of 0.10 mg/day of copper.
Perhaps more impressive is similar treat
ment of a 36-year old woman during a 10month
period in a hospital following resec
tion of her intestinal tract between the
duodenum and descending colon (790).
During her hospitalization she gained 34
pounds. Subsequently, after mastering the
technique of administering her parenteral
fluids at home, she was able to carry out
her household duties effectively. Through
out the postoperative period her parenteral
solution provided 0.018 mg/day of copper.
The only other source of copper, the 100
mg of protein hydrolysate, might have
provided about 0.075 mg/day and ac
counted for a total intake of 0.093 mg/day.
Essentially the same experience, with em
ployment of a similar parenteral fluid sup
plemented with 0.06 mg/day is reported
by Langer et al. (441) in the management
of two women, 21 and 34 years of age, fol
lowing extensive intestinal resection. These
two reports (441, 790) appear to indicate
that the minimal daily intravenous require
ment for adult man may well be less than
the proposed additions of 0.3 to 0.4 mg/day
Downloaded from
jn.nutrition.org
by guest on February 27, 2013