of athletes suffering from true iron defi-
ciency anaemia is therefore difficult to establish
(Eichner 1988). Further debates have been
sparked by the fact that many athletes with low
iron stores eat little haem iron and yet have
no performance decrements (Dallongeville et al.
1989; Snyder et al.1989; Lyle et al.1992; Pate et al.
1993; Williford et al.1993). It is, however, impor-
tant to monitor iron status among athletes, espe-
cially female athletes. The Sports Medicine and
Science Division of the United States Olympic
Committee recommend screening for haemoglo-
bin and haematocrit twice yearly. Other tests
of iron stores are recommended based on men-
struation records.
Snyderet al.(1989) investigated the iron intake
and iron stores in female athletes who either
were consuming a mixed diet or were classified
as a modified vegetarian. The subjects were
matched for age, body mass, aerobic capacity,
training load and number of pregnancies. The
modified vegetarians (n=9) consumed less than
100 g of red meat per week while the subjects on
the mixed diet (n=9) included red meat in their
diet. Both groups consumed the same amount of
iron (14 mg · day–1), but serum ferritin and total
iron-binding capacity were significantly lower in
the modified vegetarian group (P<0.05). The
authors also found that the bioavailability of the
iron consumed by the two groups was different.
Iron consumed by the modified vegetarian
group was significantly less available than the
iron consumed by the mixed-diet group. These
data suggest that in female runners non-haem
iron may not be as readily available as haem iron.
These findings have also been confirmed in the
non-athletic population. In 1995 Shaw et al.
(1995) investigated the iron status of young
Chinese Buddhist vegetarians (23 men and 32
women) and compared them with non-vegetar-
ian students (20 men and 39 women). Dietary
assessment of iron intake and haematological
measurements of biochemical indices, including
haemoglobin, plasma iron, transferrin saturation
and plasma ferritin, were made. A characteristic
of the vegetarian diets was that most of the
protein was coming from soybean products,
448 special considerations
which have limited bioavailable iron. Daily iron
intake was similar in both vegetarian and non-
vegetarian men, but iron intake was significantly
higher in female vegetarians than non-
vegetarians. Results from the haematological
measurements showed that for both sexes, the
median plasma ferritin concentration of the veg-
etarians was about half that of the non-
vegetarians. There was also a greater prevalence
of low ferritin levels and anaemia in the vegetar-
ian group, especially among the vegetarian
women.food strategies for increasing
iron in a vegetarian diet
Because animal foods are the best and most
absorbable source of iron, this presents a poten-
tial problem to the vegetarian who eats no red
meat. Lacto-ovovegetarians also have a problem
consuming enough iron, as milk and dairy
products are poor sources of iron. Vegetarians
can incorporate leafy green vegetables such as
spinach and legumes as well as fortified and
enriched whole grains into their diets. Dried fruit
can also provide iron in the vegetarian diet.
Dietary iron may also be derived from iron
cooking utensils. When acidic foods are cooked
in iron cookware, some of the iron is taken up
with the food.Zinc status among athletes
Since the best food sources of zinc are meats,
dairy products and seafood (especially oysters),
zinc nutriture is of concern for vegetarians.
Whole-grain cereals and cereal products are the
primary sources of zinc in many vegetarian diets,
but the phytate and fibre content of these prod-
ucts reduces the bioavailability of zinc (Reinhold
et al.1976). Zinc is found in almost every tissue in
the body and is a cofactor for over 100 enzymes,
of which several are important in the pathways
for energy metabolism. Zinc is also needed
for protein synthesis and is a part of the insulin
molecule.
Several studies have demonstrated that