Pediatric Nutrition in Practice

Vitamins and Trace Elements 65

1

tary foods during the weaning process [9]. Of
course, in individuals receiving part or all of their
nutrition via the intravenous parenteral route, at-
tention must be paid to perfuse micronutrients as
well to avoid deficiency [10].
Secondary micronutrient undernutrition is re-
lated to the failure to absorb, to utilize or to retain
the nutrient in the body once ingested with the
diet or a supplement. Table  3 classifies and illus-
trates the factors affecting micronutrient disposi-
tion. These factors come into interplay in severe
diseases commonly seen in pediatric practice,
such as repeated or chronic diarrhea, Crohn’s dis-
ease [11] , untreated celiac disease or cystic fibrosis.

There is a narrow spectrum of situations in

which there is excessive absorption or retention

of certain trace elements, leading to progressive

accumulation and eventual overload. This oc-

curs with iron in conditions called hemochro-

matosis and hemosiderosis due to disruption of

the intestinal regulation of its uptake. It also oc-

curs with copper in that the absorbed metal can-

not be normally exported from the cells after its

uptake due to a genetic mutation. In both in-

stances, these metals accumulate in selected or-

gans, producing oxidative and degenerative

damage.

Theoretical and Practical Precautions and

Caveats regarding Vitamin and Trace Element

Nutrition

On the one hand, considerations based on cli-

mate, environmental conditions and endemic in-

fectious diseases may modify the conventional re-

quirements of certain micronutrients, usually in-

creasing the demand to support nutrition and

growth. Even ethnic origin can be seen as an

emerging factor, as genetic polymorphisms that

influence micronutrient handling are increasing-

ly being recognized [12].

On the other hand, pathogenic viruses, bacte-

ria, protozoa and fungi have their own specific

requirements of certain trace elements such as

iron, zinc and manganese. The malarial organ-

ism (Plasmodium) and pathogenic amoeba (e.g.

Entamoeba histolytica ) and their inf luence on the

iron status of the host are cases in point. In situ-

ations in which sanitary or antimicrobial control

cannot stem parasitic transmission, individuals

having lower reserves of iron may be relatively

protected against the proliferation of these patho-

gens.

The overall balance between micronutrients,

both in the diet (on the plate) and in the body

(in tissues and organs), has implications because

a series of recognized nutrient-nutrient interac-

Ta b l e 3. Factors conditioning the absorption and utiliza-
tion of dietary micronutrients

Inhibition of intestinal uptake
Environmental enteropathy under unsanitary
conditions
Dietary constituents that interfere with nutrient
absorption, such as dietary fibers and phytic acid
Intestinal parasites (Helicobacter pylori, protozoa and
helminths)
Active acute, recurrent or chronic persistent
gastroenteritis

Impairment of nutrient utilization
Lead exposure interferes with the incorporation of iron
into hemoglobin, leading to anemia
Inflammation, chronic illness and, specifically, renal
disease disrupt the mobilization of diverse nutrients
to the red cells, leading to anemia
Menkes disease impairs the cellular utilization of copper

Enhanced destruction of vitamins
As organic compounds, vitamins can be denatured or
metabolized, as happens with vitamin E in the
presence of oxidants
Tobacco smoking destroys vitamin C
Note: inorganic substances (trace elements) cannot be
destroyed

Increased nutrient wastage
The metabolic consequences of a systemic
inflammatory response leads to excessive urinary
excretion of nitrogen, zinc and vitamin A
Abuse of cathartic laxatives induces excessive losses of
water, sodium, potassium, magnesium and calcium

Koletzko B, et al. (eds): Pediatric Nutrition in Practice. World Rev Nutr Diet. Basel, Karger, 2015, vol 113, pp 62–67
DOI: 10.1159/000367871