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Trace element supplementation after major burns increases burned skin
trace element concentrations and modulates local protein metabolism
but not whole-body substrate metabolism.Am
J Clin Nutr. 2007 May;85(5):1301-6.
BACKGROUND: After
major burns, patients exhibit an intense catabolism, and the wounds
require surgery and grafting for closure. Complications, such as
weight loss and delayed wound healing, are worsened by trace element
(TE) deficiencies. OBJECTIVE: We aimed to assess the effects of TE
supplements on systemic substrate turnover and local protein
metabolism during wound healing after major burns. DESIGN: This was a
prospective, randomized, placebo-controlled trial in 21 patients aged
35 +/- 11 y with burns on 45 +/- 16% of their body surface area; 12
had skin biopsies performed on days 3, 10, and 20, and 10 patients
underwent a stable-isotope investigation on day 10. Intravenous
copper, selenium, and zinc (TE group) or vehicle (V group) was given
with a saline solution for 14-21 d. On day 10, [(13)C]phenylalanine
(600-microg/kg bolus followed by 12 microg x kg(-1) x min(-1)) plus
6-[(2)H(2)]glucose and [(2)H(5)]glycerol were infused for 6 h to
determine skin protein turnover. Biopsies were performed 1 and 6 h
after the start of infusion to determine [(13)C]phenylalanine
enrichment. RESULTS: The patients' mean age and burn severity did not
differ significantly between the groups nor between the skin
investigations subgroups. Plasma TE concentrations were significantly
higher in the TE group. In the burned areas, the skin contents of
selenium (P=0.02) and zinc (P=0.03) increased by day 20. The
supernatant-to-plasma (13)C enrichment ratio in burned skin was 0.363
+/- 0.094 (TE group) and 0.286 +/- 0.130 (V group) after 1 h (NS) and
0.592 +/- 0.153 (TE group) and 0.262 +/- 0.171 (V group) after 6 h,
which reflected lower catabolism in the TE group (P=0.03). No
significant differences in whole-body substrate turnover were found
between the groups. CONCLUSION: TE supplementation was associated with
an increased skin tissue content of selenium and zinc and with a
reduction in skin protein catabolism.
Zinc deficiency: a special challenge.J
Nutr. 2007 Apr;137(4):1101-5.
In the
development and testing of programs designed to improve complementary
feeding globally, local nonfortified food-based solutions comprise an
important strategy for the foreseeable future. These solutions are
especially vital for the rural poor of less-developed countries. Zinc
is notable among individual nutrients that have been designated as
"problem" nutrients, adequate intake of which is difficult from
complementary foods without fortification. This article considers the
potential role of meat +/- liver in addressing this apparent problem.
In a recent Colorado study, beef and cereal have been determined to be
equally acceptable between age 5-7 mo as first and regular
complementary foods. Average intake and absorption of Zn from beef by
7 mo of age, together with the modest intake/absorption of Zn from
breast milk at that age, were adequate to meet average dietary and
physiologic zinc requirements, respectively. Barriers to acceptability
and availability of affordable meat are considered, but these are
neither universal nor irresolvable in all populations.
Reduction of nosocomial pneumonia after major burns by trace element
supplementation: aggregation of two randomised trials.Crit
Care. 2006;10(6):R153
INTRODUCTION:
Nosocomial pneumonia is a major source of morbidity and mortality
after severe burns. Burned patients suffer trace element deficiencies
and depressed antioxidant and immune defences. This study aimed at
determining the effect of trace element supplementation on nosocomial
or intensive care unit (ICU)-acquired pneumonia. METHODS: Two
consecutive, randomised, double-blinded, supplementation studies
including two homogeneous groups of 41 severely burned patients (20
placebo and 21 intervention) admitted to the burn centre of a
university hospital were combined. Intervention consisted of
intravenous trace element supplements (copper 2.5 to 3.1 mg/day,
selenium 315 to 380 mug/day, and zinc 26.2 to 31.4 mg/day) for 8 to 21
days versus placebo. Endpoints were infections during the first 30
days (predefined criteria for pneumonia, bacteraemia, wound, urine,
and other), wound healing, and length of ICU stay. Plasma and skin
(study 2) concentrations of selenium and zinc were determined on days
3, 10, and 20. RESULTS: The patients, 42 +/- 15 years old, were burned
on 46% +/- 19% of body surface: the combined characteristics of the
patients did not differ between the groups. Plasma trace element
concentrations and antioxidative capacity were significantly enhanced
with normalisation of plasma selenium, zinc, and glutathione
peroxidase concentrations in plasma and skin in the trace
element-supplemented group. A significant reduction in number of
infections was observed in the supplemented patients, which decreased
from 3.5 +/- 1.2 to 2.0 +/- 1.0 episodes per patient in placebo group
(p < 0.001). This was related to a reduction of nosocomial pneumonia,
which occurred in 16 (80%) patients versus seven (33%) patients,
respectively (p < 0.001), and of ventilator-associated pneumonia from
13 to six episodes, respectively (p = 0.023). CONCLUSION: Enhancing
trace element status and antioxidant defences by selenium, zinc, and
copper supplementation was associated with a decrease of nosocomial
pneumonia in critically ill, severely burned patients.
Effects of nutrients (in food) on the structure and
function of the nervous system: update on dietary requirements for
brain. Part 1: micronutrients.J
Nutr Health Aging. 2006 Sep-Oct;10(5):377-85.
The objective of
this update is to give an overview of the effects of dietary nutrients
on the structure and certain functions of the brain. As any other
organ, the brain is elaborated from substances present in the diet
(sometimes exclusively, for vitamins, minerals, essential amino-acids
and essential fatty acids, including omega- 3 polyunsaturated fatty
acids). However, for long it was not fully accepted that food can have
an influence on brain structure, and thus on its function, including
cognitive and intellectuals. In fact, most micronutrients (vitamins
and trace-elements) have been directly evaluated in the setting of
cerebral functioning. For instance, to produce energy, the use of
glucose by nervous tissue implies the presence of vitamin B1; this
vitamin modulates cognitive performance, especially in the elderly.
Vitamin B9 preserves brain during its development and memory during
ageing. Vitamin B6 is likely to benefit in treating premenstrual
depression. Vitamins B6 and B12, among others, are directly involved
in the synthesis of some neurotransmitters. Vitamin B12 delays the
onset of signs of dementia (and blood abnormalities), provided it is
administered in a precise clinical timing window, before the onset of
the first symptoms. Supplementation with cobalamin improves cerebral
and cognitive functions in the elderly; it frequently improves the
functioning of factors related to the frontal lobe, as well as the
language function of those with cognitive disorders. Adolescents who
have a borderline level of vitamin B12 develop signs of cognitive
changes. In the brain, the nerve endings contain the highest
concentrations of vitamin C in the human body (after the suprarenal
glands). Vitamin D (or certain of its analogues) could be of interest
in the prevention of various aspects of neurodegenerative or
neuroimmune diseases. Among the various vitamin E components (tocopherols
and tocotrienols), only alpha-tocopherol is actively uptaken by the
brain and is directly involved in nervous membranes protection. Even
vitamin K has been involved in nervous tissue biochemistry. Iron is
necessary to ensure oxygenation and to produce energy in the cerebral
parenchyma (via cytochrome oxidase), and for the synthesis of
neurotransmitters and myelin; iron deficiency is found in children
with attention-deficit/hyperactivity disorder. Iron concentrations in
the umbilical artery are critical during the development of the foetus,
and in relation with the IQ in the child; infantile anaemia with its
associated iron deficiency is linked to perturbation of the
development of cognitive functions. Iron deficiency anaemia is common,
particularly in women, and is associated, for instance, with apathy,
depression and rapid fatigue when exercising. Lithium importance, at
least in psychiatry, is known for a long time. Magnesium plays
important roles in all the major metabolisms: in oxidation-reduction
and in ionic regulation, among others. Zinc participates among others
in the perception of taste. An unbalanced copper metabolism
homeostasis (due to dietary deficiency) could be linked to Alzheimer
disease. The iodine provided by the thyroid hormone ensures the energy
metabolism of the cerebral cells; the dietary reduction of iodine
during pregnancy induces severe cerebral dysfunction, actually leading
to cretinism. Among many mechanisms, manganese, copper, and zinc
participate in enzymatic mechanisms that protect against free
radicals, toxic derivatives of oxygen. More specifically, the full
genetic potential of the child for physical growth ad mental
development may be compromised due to deficiency (even subclinical) of
micronutrients. Children and adolescents with poor nutritional status
are exposed to alterations of mental and behavioural functions that
can be corrected by dietary measures, but only to certain extend.
Indeed, nutrient composition and meal pattern can exert either
immediate or long-term effects, beneficial or adverse. Brain diseases
during aging can also be due to failure for protective mechanism, due
to dietary deficiencies, for instance in anti-oxidants and nutrients
(trace elements, vitamins, non essential micronutrients such as
polyphenols) related with protection against free radicals.
Macronutrients are presented in the accompanying paper.
Zinc in human health.P
N G Med J. 2004 Sep-Dec;47(3-4):146-58.
Malnutrition is a
contributing cause of about half of the 10 million deaths annually
worldwide, and contributes to a substantial proportion of the
infectious disease morbidity among children in developing countries.
Recent epidemiological and clinical evidence has shown that in most
developing countries deficiencies of specific micronutrients are
partly responsible for the severity of infectious disease morbidity
and mortality in malnourished children. Efforts to improve
micronutrient status have focused on iron, vitamin A and iodine.
Supplementation with iron and vitamin A significantly reduces child
mortality, while implementation of the universal salt iodization
strategy reduces the incidence of iodine deficiency disorders. These
strategies are considered to be among the most cost-effective health
interventions in developing countries. A number of recent zinc
supplementation studies in developing countries suggest that greater
priority should also be given to the correction of mild to moderate
zinc deficiency in children, pregnant women and lactating mothers.
Some of these studies showed that zinc supplementation reduces the
duration of malaria, and the severity of diarrhoea and respiratory
infections (including pneumonia), and improves immunocompetence in
susceptible children. The results of these studies indicate that zinc
may be another specific micronutrient in which there is widespread
deficiency in developing countries and that great benefits can be
achieved by its supplementation.
Dietary zinc and iron sources, physical growth and cognitive
development of breastfed infants.J
Nutr. 2000 Feb;130(2S Suppl):358S-360S.
Iron and zinc are
trace minerals that are of critical importance to the young infant for
normal growth and development. Exclusive feeding of human milk
provides adequate amounts of both of these nutrients for normal term
infants for approximately the first 6 mo. of life. Current
recommendations for introduction of complementary foods at this age do
not emphasize the order of introduction of specific foods because the
infant's gastrointestinal tract is considered mature at this time.
Consideration of nutritional needs at 6 mo. has generally focused on
the increasing risk of iron deficiency the longer the diet is without
an additional source of iron. Recently, there has been more
recognition of the risk of zinc deficiency in the second half of the
first year of life in breastfed infants. Review of common feeding
practices indicates that early complementary foods are typically iron
fortified but low in zinc. Several studies have now investigated the
effects of meat as an earlier complementary food on iron and zinc
status. Results of these studies, although requiring further
verification, suggest that increased meat intake by breastfed infants
>6 mo. old would adequately support both iron and zinc requirements.
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