Calcium
DEFINITION
Calcium is an essential mineral that is the most abundant type
of mineral in the body.
of mineral in the body.
DESCRIPTION
About 99% of the body’s Calcium is contained in the skeleton
in the form of Calcium crystals. Calcium is very important for the
formation of strong, healthy bones and for decreasing the risks of
bone fractures and osteoporosis. Even after bone growth has
stopped, there is a constant process of bone remodelling that takes
place. Dietary Calcium is required throughout life to enable new
bone to form. Calcium exists in the body fluids as a particle
called an ion, which carries a small, positive electric charge.
This property allows Calcium ions to conduct electrical impulses in
nerve and muscle cells, which allow nerves to transmit signals in
the body and allow the muscles of the body to contract.
in the form of Calcium crystals. Calcium is very important for the
formation of strong, healthy bones and for decreasing the risks of
bone fractures and osteoporosis. Even after bone growth has
stopped, there is a constant process of bone remodelling that takes
place. Dietary Calcium is required throughout life to enable new
bone to form. Calcium exists in the body fluids as a particle
called an ion, which carries a small, positive electric charge.
This property allows Calcium ions to conduct electrical impulses in
nerve and muscle cells, which allow nerves to transmit signals in
the body and allow the muscles of the body to contract.
Calcium is also essential for the contraction of the heart as well
as for the release of certain hormones and other chemicals in the
body. Among these chemicals are the neurotransmitters: specialised
‘signal’ chemicals that help the nerves throughout the body
communicate with one another. Calcium is also an important part of
many enzymes and other proteins in the body. Enzymes are special
substances that speed up chemical reactions in the body. Calcium
also assists in the blood clotting process.
as for the release of certain hormones and other chemicals in the
body. Among these chemicals are the neurotransmitters: specialised
‘signal’ chemicals that help the nerves throughout the body
communicate with one another. Calcium is also an important part of
many enzymes and other proteins in the body. Enzymes are special
substances that speed up chemical reactions in the body. Calcium
also assists in the blood clotting process.
The Calcium levels in the body are very tightly controlled by
hormones as well as vitamin D. Very high Calcium levels in the body
can cause Calcium toxicity, but this usually only occurs in certain
diseases that decrease the ability of the kidney to secrete Calcium
in the urine. High Calcium levels can be caused by an excess of
vitamin D in the body, as this vitamin changes the metabolism of
Calcium so its levels build up in the body. Milk-alkali syndrome is
a syndrome where a person suffers Calcium toxicity that is caused
by consuming large amounts of dietary Calcium while taking certain
peptic ulcer medications to reduce the acidity of the stomach. This
medication reduces the body’s capacity to excrete calcium.
Short-term, high Calcium levels in the body can cause loss of
appetite, vomiting, abdominal pain, constipation, confusion,
psychosis and even coma. Long-term effects of elevated Calcium
levels include the formation of calcium-rich kidney stones.
hormones as well as vitamin D. Very high Calcium levels in the body
can cause Calcium toxicity, but this usually only occurs in certain
diseases that decrease the ability of the kidney to secrete Calcium
in the urine. High Calcium levels can be caused by an excess of
vitamin D in the body, as this vitamin changes the metabolism of
Calcium so its levels build up in the body. Milk-alkali syndrome is
a syndrome where a person suffers Calcium toxicity that is caused
by consuming large amounts of dietary Calcium while taking certain
peptic ulcer medications to reduce the acidity of the stomach. This
medication reduces the body’s capacity to excrete calcium.
Short-term, high Calcium levels in the body can cause loss of
appetite, vomiting, abdominal pain, constipation, confusion,
psychosis and even coma. Long-term effects of elevated Calcium
levels include the formation of calcium-rich kidney stones.
DEFICIENCY
Calcium deficiency can be caused by certain hormonal
deficiency diseases, including hypoparathyroidism, as well as
vitamin D deficiency, kidney disease, magnesium deficiency,
diseases of the pancreas and other medical conditions. Symptoms and
signs of Calcium deficiency include muscle cramps; osteoporosis;
confusion; depression; psychosis; cataracts; poor sensation in the
hands, feet, lips and tongue; involuntary muscle twitching; heart
rhythm disturbances; dry and brittle nails and coarse hair.
deficiency diseases, including hypoparathyroidism, as well as
vitamin D deficiency, kidney disease, magnesium deficiency,
diseases of the pancreas and other medical conditions. Symptoms and
signs of Calcium deficiency include muscle cramps; osteoporosis;
confusion; depression; psychosis; cataracts; poor sensation in the
hands, feet, lips and tongue; involuntary muscle twitching; heart
rhythm disturbances; dry and brittle nails and coarse hair.
SOURCES
Dairy products contain large amounts of Calcium that is in a
form that is easily absorbed. Non-dairy sources of Calcium include
tofu that is chemically set with Calcium, dried beans, kale,
broccoli and bok choy.
form that is easily absorbed. Non-dairy sources of Calcium include
tofu that is chemically set with Calcium, dried beans, kale,
broccoli and bok choy.
There are various Calcium supplements available and these
should generally be taken with vitamin D to improve the absorption
of Calcium from the intestines. People with kidney disease are
generally advised by their Doctor to take a supplement that
prevents the absorption of phosphate, such as calcium
carbonate.
should generally be taken with vitamin D to improve the absorption
of Calcium from the intestines. People with kidney disease are
generally advised by their Doctor to take a supplement that
prevents the absorption of phosphate, such as calcium
carbonate.
SUPPLEMENTS
The key factor to consider when selecting a Calcium supplement
is the amount of elemental calcium the product contains. The term
‘elemental Calcium’ refers to the actual amount of Calcium in a
supplement that is available for the body to absorb. Most Calcium
supplements list the amount of elemental Calcium on the label. In
some cases only the total weight of each tablet, in milligrams
(mg), is listed. This is the weight of the Calcium, plus whatever
it is bound to, such as carbonate, citrate, lactate or gluconate.
Some of the types of Calcium supplements that are available
include:
is the amount of elemental calcium the product contains. The term
‘elemental Calcium’ refers to the actual amount of Calcium in a
supplement that is available for the body to absorb. Most Calcium
supplements list the amount of elemental Calcium on the label. In
some cases only the total weight of each tablet, in milligrams
(mg), is listed. This is the weight of the Calcium, plus whatever
it is bound to, such as carbonate, citrate, lactate or gluconate.
Some of the types of Calcium supplements that are available
include:
MICROCRYSTALLINE HYDROXYAPATITE
Advantages: best absorbed source, complete bone food
containing a variety of minerals, amino acids and protein matrix
like human bone, shown to increase bone density, may help to stop
bone loss, better absorbed by people with poor digestive absorption
than other forms of calcium.
containing a variety of minerals, amino acids and protein matrix
like human bone, shown to increase bone density, may help to stop
bone loss, better absorbed by people with poor digestive absorption
than other forms of calcium.
Disadvantages: none.
CALCIUM CITRATE
Advantages: very well absorbed, reduced risk of kidney stones,
well absorbed by those with poor digestive absorption.
well absorbed by those with poor digestive absorption.
Disadvantages: not a complete bone food.
CALCIUM OROTATE
Advantages: may promote bone mineralisation, well
absorbed.
absorbed.
Disadvantages: not a complete bone food, lower level of
elemental calcium, a high dose is required to provide enough
calcium.
elemental calcium, a high dose is required to provide enough
calcium.
CALCIUM LACTATE
Advantages: well absorbed.
Disadvantages: not a complete bone food, may contain milk or
yeast by-products. (Sourced from milk, sugar, starch or whey with
calcium carbonate).
yeast by-products. (Sourced from milk, sugar, starch or whey with
calcium carbonate).
CALCIUM CARBONATE
Advantages: cheapest form of calcium.
Disadvantages: not a complete bone food, malabsorbed by those
with poor digestion, poor absorption in older people, it has an
antacid effect that interferes with digestion. This type of Calcium
is best taken with food to enhance absorption. Some calcium
carbonate supplements may be sourced from oyster shells or coral,
while others are sourced from limestone. These oyster shell and
coral-based supplements are not suitable for a person with an
allergy to shellfish. If the manufacturer cannot verify the source,
choose a supplement containing another form of calcium, such as
calcium citrate.
with poor digestion, poor absorption in older people, it has an
antacid effect that interferes with digestion. This type of Calcium
is best taken with food to enhance absorption. Some calcium
carbonate supplements may be sourced from oyster shells or coral,
while others are sourced from limestone. These oyster shell and
coral-based supplements are not suitable for a person with an
allergy to shellfish. If the manufacturer cannot verify the source,
choose a supplement containing another form of calcium, such as
calcium citrate.
BONE MEAL
Advantages: contains multiple minerals needed for
bone.
bone.
Disadvantages: may contain high levels of lead, arsenic and
cadmium, some of the organic constituents are destroyed leading to
reduced effectiveness.
cadmium, some of the organic constituents are destroyed leading to
reduced effectiveness.
Ask your Pharmacist which supplement is best for you.
DOSAGE
The recommended dietary intake (RDI) for Calcium is 800 mg per
day for adult males and 800 mg per day for adult females until the
age of 54. Women over 54 years of age require 1000 mg of Calcium
per day. Women who are pregnant require an additional 300 mg of
Calcium per day and those who are breastfeeding require an extra
400 mg per day.
day for adult males and 800 mg per day for adult females until the
age of 54. Women over 54 years of age require 1000 mg of Calcium
per day. Women who are pregnant require an additional 300 mg of
Calcium per day and those who are breastfeeding require an extra
400 mg per day.