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Calcium
Calcium is the mineral in our bodies that forms our bones and keeps them strong.
Ninety-nine percent of the calcium in our bodies is stored in the bones and
teeth and is responsible for the strength and hardness of these structures.
The remaining 1%, found in the blood and soft tissues, is vital to our health.
This 1% of calcium is responsible for our muscles contracting correctly, our
blood clotting and our nerves carrying messages. Hormones and Vitamin D continuously
move calcium from our bones to our bloodstream, and vice versa. Almost all body
functions in some way depend on calcium. The central nervous system, for example,
depends on calcium to keep the nerves functioning properly.
Why do we need calcium?
We get this crucial 1% of calcium from two sources: the calcium found in our
diets, and the calcium stored in our bones. Bones have two main roles in our
bodies: maintaining our body structure, and acting as a “reserve” supply of
calcium. Our bodies are constantly tearing down and rebuilding bone in order
to provide enough calcium for all our body functions. We lose calcium every
day through shed skin, nails, hair, and sweat, and through through urine and
feces. Ideally, our diets should provide us with enough calcium to maintain
this other 1%. If, however, we lack calcium in our diets, our bodies make up
the difference by taking calcium out of the reserve supply in our bones.
This pattern can become dangerous over time, as eventually our bodies might
tear down bone quicker than they can replace it. The result of this pattern
is osteoperosis, a disease in which bones become weak and brittle. The skeleton
shrinks; the bones become prone to fracture and breakage. Symptoms of osteoperosis
typically first appear sometime after the age of forty. Post-menopausal women
are at the greatest risk for osteoperosis. These women experience reduced levels
of estrogen, a hormone which, among other functions, aids with the absorption
of calcium.
Another problem associated with calcium deficiency is hypocalacemia. This condition
deals with a low level of calcium in the blood and tissues, and is characterized
by tingling sensations, numbness, and muscle twitches throughout the body. If
these symptoms persist, they can lead to a more severe condition called tetany,
where the muscle twitches evolve into muscle spasms. Tetany is more often caused
by a hormonal imbalance in the regulation of calcium rather than a dietary deficiency.
How do I know if I am calcium-deficient?
The “reserve” calcium in our bones is very alkaline. In order to be used for
bodily functions, it must first circulate in the bloodstream long enough in
order to acidify. Only once it has acidified can the body use it. Thus, a good
indication of calcium deficiency is evidence of excessive calcium in the blood
(determined by a blood test). Excessive calcium suggests that reserve calcium
is swimming around, trying to acidify.
Sources of calcium
The milk products food group is the biggest source of calcium. At least 2-3
servings from this group a day are recommended. Some other foods are calcium-rich
as well. Get your daily doses of calcium from the following:
· Milk
· Yogurt
· Cheese
· Dark green vegetables
· Nuts
· Grains
· Beans
· Canned salmon
· Canned sardines
· Tofu
How much calcium do I need?
Calcium supplements are available in tablets, capsules or liquid form.
The recommended daily calcium intake is 1000-1200 mg/day for adult men and
women. Dairy products remain the biggest and best source of calcium. If your
diet lacks dairy products, consider including calcium supplements as part of
your diet. Calcium exists in nature only in combination with other substances
called compounds. Several different calcium compounds are used in supplements,
including calcium carbonate, calcium phosphate and calcium citrate. These compounds
contain different amounts of elemental calcium, the actual amount of calcium
in the supplement. This means you have to be careful: 1000mg of calcium phosphate,
for example, does not mean you are actually getting 1000mg of calcium. Read
the label of your supplement carefully to determine how much elemental calcium
is in the supplement. This information will help you determine how many doses
or pills to take.
When choosing a calcium supplement, check its absorbability. A good calcium
tablet should be absorbed easily in the body. Hopefully, the label will state
that the tablets are absorbable. If not, place the tablet in a small amount
of warm water for 30 minutes. If the tablet has not dissolved within this time,
it probably will not dissolve in the stomach. Chewable and liquid calcium supplements
dissolve are broken down before they enter the stomach, so they dissolve easily.
What are the side effects of calcium supplements?
Most people tolerate calcium supplements well. However, some people report
experiencing gas or constipation. Increased fluid and/or fiber intake should
combat this problem. Also, consult with your doctor before taking any prescription
medicine in combination with calcium supplements to avoid unpleasant interactions.
Calcium and Vegans
A common misconception is that vegans, who do not eat any animal products,
are calcium-deficient. This is not necessarily true, as calcium is found in
many vegan-friendly foods such as dark leafy vegetables, beans and tofu. Omnivores
should be aware: a connection exists between protein consumption and calcium
lost in the urine, so high-protein diets are actually more likely to result
in calcium deficiency. For every gram of protein consumed, 10 mg of calcium
should be consumed as well.
What if I have too much calcium?
Excess calcium in the blood can cause nausea, vomiting and calcium deposition
in the heart and kidneys.
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