Calcium
is an essential mineral and plays an important
role in the body. Calcium helps repair bones; it
is necessary for the normal functioning of nerves,
muscle contractions, and blood clotting and also
protects heart health. It is also helpful in
managing the secretion of insulin and hormones and
in preventing osteoporosis. Calcium also tightens
the LES though this is not an antacid effect.
Calcium is never found free in nature because it
forms compounds known as calcium salts e.g.
calcium citrate, calcium
carbonate, calcium phosphate, etc. The label
"elemental" designates the percentage of the
substance that is pure calcium.
The
recommended calcium intake for adults is 1000 mg
to 1300 mg daily depending upon age and gender.
Pregnant, breast feeding and menopausal women
require more dietary calcium. Calcium supplements
may be taken as calcium carbonate or calcium
citrate. They are appropriate for people with GERD
with antacids and H2 antagonists and prescription
medications such as
Prilosec.
Regular
use of antacids, used in the treatment of GERD,
causes a decrease in gastric acid called
hypochlorhydria which affects the absorption of
important minerals one of them being calcium which
in turn increases the risk of hip fractures
particularly in older patients. Patients who have
been on long term proton pump inhibitor therapy
for GERD should be routinely screened for
osteoporosis. Older adults who require long-term
therapy with proton pump inhibitors should be
advised to take calcium supplements, particularly
calcium citrate because it does not require
stomach acid to be absorbed like other calcium
salts. In addition, it causes much less bloating
and gas than calcium carbonate. Calcium carbonate
is an insoluble salt and must be ionized by the
stomach before it is absorbed. In older patients
who are severely deficient in stomach acid, barely
4% of the calcium in this form is absorbed.
Although calcium citrate is also an antacid, it is
already in a form that the body can use and is
absorbed more efficiently. But it is more
expensive and has half the elemental calcium as
that of calcium carbonate.
On
the other hand, calcium citrate enhances
the absorption of aluminum from the aluminum
hydroxide present in some antacids. The two must
not be prescribed together especially in patients
with impaired renal function. Aluminum is excreted
by the kidneys and toxic amounts can impair kidney
function. It can also accumulate in the brain and
cause seizures and reduced mental alertness.
Fortunately, calcium citrate does not
interfere with iron absorption and it also binds
with oxalates to prevent renal stone formation.
