According to 1994 data, 73% of calcium in the US food supply is
from milk products, 9% is from fruits and vegetables, 5% is from
grain products, and the remaining 12% is from all other sources
(Young et al., 1997). Although not particularly rich in calcium,
grains consumed in large quantities can substantially increase
the dietary calcium content. Moreover, some kinds of grain derivate
products, such as breakfast cereals, can be enriched with calcium,
hence becoming a high-calcium nutrient. In this sense,
determining the Ca amount in manufactured cereals is important
for quality control procedures.