What
Is Calcium And Why Is It Good For Us?
Most
of us have heard of calcium and know it is good for our bones. This
is particularly true for those of us brought up in the West, where we
were seemingly forever being told by our parents to 'drink your
milk'.
This article is Part 5 in our 5 part series on nutritional deficiencies. To view the Vitamin D deficiency article, click here and to view the Magnesium deficiency article, click here.
Calcium
is indeed a mineral needed to keep bones strong, but it also carries
out a number of other functions in the body. Most of the calcium in
our bodies is stored within our bones but some is also required to
move muscles, transport blood around the body, and in carrying
messages from the brain, through the nerves, to other parts of the
body. It also supports the releasing of enzymes and hormones which
impact on all areas of functioning.
What
Foods Contain Calcium?
Dairy
products are the primary source of calcium for many people. All
forms of dairy (milk, cheese, yoghurt) contain dairy, but if you do
consume a great deal of dairy it may be best to choose healthy
options as some products can contribute to high cholesterol.
For
individuals who don't eat dairy regularly, either through choice or
necessity, there are other ways to incorporate calcium into your
diet. Broccoli and kale are excellent vegetarian sources of calcium
and fish with edible bones, e.g. tinned salmon, are great
meat-product options.
Most
grains also provide a certain, albeit lower, level of calcium, and
nowadays many products have calcium added in artificially, just read
the label to find out levels.
Recommended
Daily Allowances And Upper Limit Of Safety
For
adults up to 50 years old the recommended daily allowance of calcium
is 1000mg, this increases to 1200mg for women up to 70 years old.
All adults over 71 years are recommended to have 1200mg of calcium
per day. This is because the body is not as adept at absorbing
calcium as we age.
Infants
are recommended to have 200mg of calcium per day in the first six
month of life, and 260mg in the second six months. Young children
(1-3 years) should receive 700mg per day raising to 1000mg up to 8
years old. From 9-18 years, children should be having 1300mg per
day, as their bones will be growing and developing a great deal
during this period. This amount should be adhered to particularly in
the case of a pregnant or breastfeeding teenager. In pregnant or
breastfeeding adults 1000mg is sufficient.
Consuming
too much calcium can cause constipation, and interfere with the
ability for the body to absorb other minerals. Receiving too much
calcium from supplements may also increase the risk of kidney stones
as these are rich in calcium oxalate. This risk doesn't appear to
hold true when high levels of calcium are achieved through food.
The
upper safety limit for adults is 2500mg and 2000mg for adults over 50
years. For infants is it 1000mg until 6 months and 1500mg to one
year. Up to 8 years the upper safely limit is 2500mg and 3000mg
until the end of the teenage years. The limit for pregnant or
breastfeeding teens the level is 3000mg, with 2500mg being the upper
limit of safety for pregnant or breasfeeding adults.
At
Risk Groups
It
seems that some of these groups, through reduced intake, do not
typically reach these levels. Of particular concern are adolescent
girls and elderly adults, these individuals are at a higher risk of
being deficient in calcium due to their reduced intake.
In
addition, some people may not consume enough calcium due to a lactose
intolerance. This occurs when people cannot digest the sugar in
milk, some are able to eat dairy products low in lactose whilst
others can choose dairy-free alternatives which are enriched with
calcium.
Vegans,
who choose not to eat animal products, are also at risk of being
deficient in calcium.
The
effect of age is particularly apparent in postmenopausal women as
they do not absorb calcium as well, and experience increased bone
loss. Calcium is vital for slowing this process. Women whose
periods have stopped for other reasons, e.g. eating too little, are
at risk of calcium deficiency due to decreased calcium absorption and
increased loss of calcium through the urine.
Some
foods can reduce the absorption of calcium, e.g. phytic acid in
grains, but this is accounted for when calculated the recommended
daily allowances, so for a well-balanced diet this shouldn't prove a
problem. Vitamin D on the other hand improves calcium absorption.
Calcium
Deficiency
Initially
if an individual is not consuming enough calcium the body takes
calcium from the bone to keep up levels in the blood necessary for
the plethora of functions calcium is required for. Over time
however, osteopenia, low bone mass, can develop as well as weak
bones, osteoporosis and fractures. Osteoporosis is a bone disease in
which the bone mineral density is extremely low, rendering the bones
fragile and susceptible to fracture.
In
addition, in those with a severe deficiency other symptoms can
develop. These include tingling and numbness in the extremities,
abnormal heart beat, convulsions, and ultimately, death.
Prevention
And Treatment
The
best treatment is of course prevention: calcium is found, either
naturally or added during processing, in a whole range of products.
In addition, it is regularly found in 'vitamins & minerals'
supplements, or as its own supplement – although the amount varies
so check the label carefully.
Calcium
Carbonate is the most widely available of the supplements, and is
best absorbed after eating. Calcium Citrate is more costly but can
be absorbed well at all times.
Calcium
is best absorbed in doses of up to 500mg, so spread your daily
consumption/supplement intake out.
Supplements
sometimes cause side-effects, including bloating and constipation.
If this occurs, try taking them with food, spreading the dose out
more or changing brand.
Calcium
supplements also interact with a number of medications, through
increased loss or decreased absorption, and occasionally the reverse.
It is really important to consult a medical professional before
commencing any course of supplements.
Prognosis
With
calcium being so widely available it may be easy to become complacent
about our intake. However, considering how vital it is throughout
our whole life, and how the effects of a lifetime of
under-consumption can effect us in our later years, when are are
already more fragile, it pays to be proactive in ensuring you make
calcium part of your daily routine.