recommended level of 0.016. The results of a
study by Huang et al.(1998) provide recent evi-
dence that the level of 0.016 mg vitamin B 6 ·g–1
protein is inadequate for young women. Their
study of eight women residing in a metabolic
unit for 92 days suggests that 0.019 mg vitamin
B 6 ·g–1protein is needed to normalize vitamin
B 6 measures to controlled baseline values. If
vitamin B 6 needs are indeed higher than current
guidelines for young women, more attention to
an adequate intake of this vitamin is needed for
female athletes.
It is advisable for those working with athletes
who typically report low energy intakes, i.e.
gymnasts, figure skaters, and runners, to appro-
priately assess food intakes while noting com-
pleteness of the nutrient data bank used to
estimate vitamin B 6 intake. Based on a thorough
assessment, one may potentially proceed to rec-
ommend consumption of additional vitamin B 6 -
rich foods.
Antioxidant vitamins
Exercise-induced oxidative stress may be a
concern for an athlete. Oxidative stress occurs
at submaximal levels of exercise (Leaf et al.
1997), and at peak V
.
o2max.(Viguie et al.1990). The
human body constantly forms free radicals and
other oxygen-derived species that can damage
DNA, lipids and proteins. When exposed to
mild oxidative stress, the body can respond by
increasing its defensive antioxidant enzymes
and proteins; however, severe damage may lead
to cell transformation and the increased oxida-
tive damage has been associated with human
disease, specifically cardiovascular disease and
cancer (Halliwell 1994).
To diminish the effect of naturally occurring
oxidative damage, it has been suggested that
antioxidant nutrients should be added to the diet
( Jacob & Burri 1996). Carotenoids, ascorbic acid,
a-tocopherol, flavonoids, and other plant pheno-
lics are a few of those suggested as important in
protecting against oxidative damage. In other
words, inclusion of fruits and vegetables in the
athlete’s diet can partially provide a solution to
the concern for increased oxidative stress from
exercise.
Some reports suggest that supplementation
with antioxidant nutrients, such as vitamin E,
can attenuate the exercise-induced lipid perox-
idation (Sumida et al.1989). A daily combination
of 294 mg vitamin E, 1000 mg ascorbic acid and
60 mg ubiquinone was found to be effective in
preventing LDL oxidation in male endurance
athletes; however, 4 weeks’ supplementation
with the antioxidant nutrients did not reduce
LDL oxidation products, i.e. conjugated dienes
(Vasankari et al.1997). Limited data specifically
on female athletes are again noted in the area of
antioxidant research.
For possible increased antioxidant vitamin
requirements for those who exercise, the recom-
mendation for an increased fruit and vegetable
intake is worthy of emphasis. Dietary guidelines
from several US organizations recommend five
or more daily servings of fruits and vegetables to
help reduce the risk of heart disease and certain
kinds of cancer ( Jacob & Burri 1996). For the
female athlete, increased intake of fruits and veg-
etables can provide additional CHO and several
essential nutrients. For those athletes limiting
energy intake to reduce body fat, these foods will
provide a higher nutrient to calorie ratio known
to be beneficial for consuming a more nutrient
adequate food intake.Minerals
Macrominerals: calcium
A nutrient worthy of consideration for supple-
mentation to the female athlete’s diet is calcium.
For detailed discussion of this mineral’s roles in
the body, calcium intake and its relationship to
exercise, refer to Chapter 23. Discussion sup-
porting the concern for adequate intake of this
mineral and of practical ways to increase calcium
intake in female athletes follows.
Peak bone mass development depends upon
adequate calcium intake during skeletal growth
(Matkovic 1991; Johnston et al.1992) as well as for
gain in bone mass until the third decade of life