Calcium – Who needs
them?
Calcium is a
mineral that is abundantly found in our body. A major part of it is in the
teeth and bones and it is responsible for giving strength and resilience to
these structures. The rest is found in nerve cells, body tissues, blood, and
other body fluids. Calcium plays a very important role in the body?s overall
health and nutrition as it contributes to many basic body functions like bone
mineralization, nerve conduction, contraction and relaxation of heart and
skeletal muscles etc. Maintaining a proper level of calcium in the body is
essential for building strong bones and teeth; clotting blood; sending and
receiving nerve signals; squeezing and relaxing muscles; releasing hormones and
other chemicals; and keeping a normal heartbeat.
Our body
regulates the level of calcium available in the blood in a narrow range to
ensure healthy functioning of nerves and muscles through various hormones.
However the main substances involved in the regulation of calcium and
phosphorus levels are vitamin D and parathyroid hormone. Since calcium is
stored primarily in the bones and teeth, these organs are the ones affected the
most when we do not have adequate calcium in the body.
Bone calcium is also used as a storage area to
release calcium into the bloodstream when it is needed. Calcium is needed
for so much more than bone health, though. Eating calcium rich foods makes it
possible for our body’s to achieve optimal nerve transmission, blood clotting,
hormone secretion and muscle contraction.
Blood calcium is tightly controlled since it
plays so many critical functions, including balancing your body’s acid/alkaline
body and pH. The body will borrow calcium from the bones as needed,
so often that the bones are actually remodeled about every 10 years.
Calcium deficiency symptoms
can include:
·
Osteopenia
or Osteoporosis
·
Tooth
decay
·
Muscle
tension
·
High
blood pressure
In order for your body to absorb calcium your
body also needs magnesium, vitamin D and vitamin K. So food sources and
complex food based supplements are preferred to isolated calcium supplements to
meet your calcium needs.
Sources of Calcium
Our body
does not produce calcium, so one must get it through external sources. Popular
food sources for calcium are dairy products. The
body can easily absorb the calcium found in milk, yogurt, cheese and
buttermilk. Phosphorous and magnesium help the body to absorb and use calcium
effectively and these two are also found in milk.
Other non-dairy
sources of calcium include green leafy vegetables such as
spinach, cauliflower, broccoli, turnip greens, mustard greens, and cabbage;
fish like salmon and sardines, seeds and nuts like sunflower seeds, almonds,
etc.
Calcium is
often added to some natural food products like orange juice, soy milk, breads,
and tofu. These can be an excellent source of calcium for people who do not
prefer dairy products in their diet.
Adequate
absorption of calcium requires exposure to sun in addition to diet. UV
radiation from the sun helps in converting vitamin Din
our body to its active form, which is required for calcium regulation.
Who should take calcium supplements?
People
usually get the required amount of calcium through diet as long as it is
balanced and incorporates some dairy and non dairy sources of calcium. However,
in certain cases, where access to a good diet is unavailable or in people who
lead a very sheltered life or in climates without adequate exposure to sun,
calcium deficiency may occur. People with lactose-intolerance (trouble in
digesting the sugar in the milk) may not be able to ingest dairy products and
hence not get enough calcium.
When the
calcium intake is insufficient, the body uses up the calcium from your
skeleton, thereby making them weak and brittle, a condition known as
osteoporosis. More severe deficiency of calcium leads to conditions called
osteomalacia and tetany, where bones become soft and fracture easily and
painful contractions of muscles occur and death may occur due to abnormality in
heart conduction.
Women are
considered to be at a higher risk of osteoporosis due to sheltered and
sedentary lifestyles along with hormonal changes following menopause (Cessation
of menstrual periods). So generally older women after
menopause, people who are not maintaining a balanced diet,
or who are unable to maintain a balanced diet for
some dietary or other health reasons, people on a vegan
diet; or people whose body is not able to
absorb enough calcium due to other health problems; people
diagnosed with osteoporosis; and people on a high-protein or
high-sodium diet which may cause your body to excrete more
calcium, are recommended to take calcium supplements.
What calcium supplements to take?
Calcium
supplements come in many forms, either as pure calcium salts or in combination
with other minerals and vitamins. A common and popular combination is calcium
with vitamin D products. To choose the right supplement one should be aware of
the required daily recommendation (RDA levels) for age and gender and whether
there are any other accompanying mineral or vitamin D deficiency.
Things to consider
If your body
doesn’t get enough calcium and vitamin D to support important functions, it
takes calcium from your bones. This is called losing bone mass. Losing bone
mass makes the inside of your bones become weak and porous. This puts you at
risk for the bone disease osteoporosis.
·
Certain populations are at higher risk for low
calcium levels, including:
·
Postmenopausal women.
·
People who have lactose intolerance and avoid
dairy products.
·
Women who have an eating disorder (for example,
anorexia).
·
People who do not eat animal, fish, or dairy
products (vegans).
·
People who take certain medicines for
osteoporosis.
· People who have parathyroid disorders,
inflammatory bowel disease, or liver or kidney disease.
Unfortunately,
getting more calcium than your body needs can cause adverse (negative) effects.
This includes kidney stones, frequent urination, belly pain, nausea/vomiting,
and fatigue. It is rare to get too much calcium from food alone. There is an
amount of calcium that most people can take each day without developing
problems. This is called the tolerable upper intake level. Doctors recommend
the following tolerable upper intake levels by age. However, this should be
interpreted in the context of any prevailing deficiencies and co-existing
health conditions.
Age group
|
Calcium
Intake/day
|
Infants
|
200-260 mg
|
1-3
|
700 mg
|
4-8
|
1000 mg
|
9-18
|
1300 mg
|
19-50
|
1000 mg
|
51-70(males)
|
1000 mg
|
51-70(Females)
|
1200 mg
|
*For
pregnant women, calcium intake is 1,300 mg/day
*Source: INSTITUTE OF MEDICINE OF THE NATIONAL ACADEMIES
