are susceptible to under-reporting of nutritional
information and for the absence of selected
micronutrients from the food tables. Hence, the
reported intake may not be true.
Few studies have been published on the
vitamin status of young athletes. Those studies
that are available suggest inadequate vitamin
consumption resulting from diets of excessive
consumption of confectionery, soft drinks and
other low nutrient-density foods (O’Connor
1994). This is contrary to the American Dietetic
Association’s (1980) stance that athletes who
consume adequate amounts of energy do not
present with vitamin deficiencies and therefore
do not require supplements. It is therefore sug-
gested that while indiscriminate use of vitamin
supplements in young athletes should be dis-
couraged, their use may be appropriate in ath-
letes who restrict their food intake (O’Connor
1994).
Iron deficiency in the absence of anaemia
is common in adolescent distance runners.
However, whether non-anaemic iron deficiency
affects athletic performance is unclear (Rowland
& Kelleher 1989). The effect of iron deficiency is
associated with incorporation of iron into
haemoglobin and other processes requiring iron
such as enzyme cofactors. However, evidence of
such deficiencies is limited; Pate et al. (1979),
Rowlandet al. (1987) and Rowland and Kelleher
(1989) all demonstrated limited evidence of
anaemia in athletic children and adolescents. In
addition, Nickerson et al. (1989) demonstrated
limited evidence of gastrointestinal bleeding in
cross-country runners with iron deficiency. It is
unlikely that non-anaemic iron deficiency will
have a significant effect upon athletic perfor-
mance. Performance may possibly be impaired
in females (see Chapter 24) with low ferritin
levels and borderline haemoglobin (12 g · dl–1).
If decrements in performance are noted, then
serum ferritin and haemoglobin are worth as-
sessing. General guidelines for the child athlete
would be to encourage eating poultry, lean red
meat, iron-enriched breakfast cereals and green
vegetables.
Calcium requirements are highest during
438 special considerations
childhood and adolescence, aside from during
pregnancy and lactation. Concern has centred on
those athletic populations whose total food, and
hence calcium, intake is likely to be low—for
example, gymnasts and dancers (O’Connor
1994). A combination of inadequate calcium
intake and amenorrhoea in these athletes has
raised serious concerns because of its association
with osteoporosis (Bailey et al.1996). Although
the effectiveness of calcium supplementation in
childhood is still unclear (Welten et al. 1994),
every effort should be made to educate young
athletes about the importance of adequate
dietary calcium.Nutritional knowledge
As already discussed, one of the major factors
that influences the nutrition of the young athlete
is a sound basis of nutritional knowledge. Work
by Richbell (1996) demonstrated in élite junior
swimmers, track and field athletes and soccer
players that whilst the three groups followed the
recommended ratio of 55 : 30 : 15 for carbohy-
drate, fat and protein intake, the nutritional
knowledge in all three disciplines was poor. This
type of pattern was also demonstrated by Perron
and Endres (1985), who assessed the dietary
intake of female volleyball players (13–17 years)
and showed that no significant correlation
existed between nutritional knowledge and atti-
tudes and dietary intake. These findings seemed
to indicate that at this age other factors such as
weight concerns and dependence on others for
food selection are significant. As previously men-
tioned by Loosli and Benson (1990), competitive
female gymnasts had poor nutritional knowl-
edge. Swedish gymnasts have been shown to
have energy intakes insufficient in relation to
their high energy needs; it is suggested that, if left
unchecked, this could affect their pubertal devel-
opment and menstrual patterns (Lindholm et al.
1995). However, although the gymnasts in this
study (Lindholm et al. 1995) had body weights at
least 1 SD below the normal weight for Swedish
children of similar chronological age, they also
had late sexual development. Therefore, inter-