Sarah H. Short, Ph.D.,Ed.D.,R.D.
Minerals are classified as major if they are needed in the diet at levels
day or more. These minerals are Calcium Ca, Phosphorus P, Magnesium Mg, Sodium
Na, Potassium K, Choride Cl.
Trace minerals are needed in amounts no higher than a
few mg/day. These include Fe, Zn, I, Se for which there are RDAs and Cu, Mn, F, Cr,
and Mo for which there are “ estimated safe and adequate” daily dietary intake
recommendation. There are other minerals needed for human nutrition, but there may
not be enough known to set recommended allowances.
Minerals are :
essential (they cannot be made in the body),
they do not provide energy,
many are needed to make
body structures such as bones,
many are needed as
activators for enzyme systems.
and can definitely be harmful if taken in excess.
50% of females are low in calcium)
The body contains more calcium than any other mineral: 99% of it is in the bone
with 1% in body fluids.
Calcium is one of the minerals necessary for bone formation (also need
phosphorous (P), magnesium (Mg), vitamin D
, and other) Bones are constantly
gaining and losing minerals. During growth, children gain more bone than they
lose. In later life, there is a gradual loss of bone.
The calcium that circulates in body fluids is absolutely necessary for life
balance of calcium in the body involves
a system of hormones and vitamin D .
Levels of calcium in fluid are maintained at the expense of bone when there is
inadequate calcium intake or absorption. If you are not getting enough calcium,
the body just takes it out of the bones to use for all the needed functions. Of
course, you are losing bone over the years.
Functions of calcium
Extra-skeletal (outside the bones)
calcium (in body fluids) is
needed for the
normal response of nerves to stimuli
membrane permeability (control of passage of fluids through cell walls).
normal rhythm of heart beat.
A high intake of Ca has been associated with lower blood pressure .
May play a role in maintaining correct body weight