Calcium - Are you getting enough? Too much?

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Calcium - Are you getting enough? Too much? JoAnn Guest Apr 28, 2005 21:04

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The solution isn't as easy as gulping milk by the gallon or popping

supplements by the handful. To call calcium the most " hyped " mineral in

history would be an understatement.

There are dozens of heavily advertised supplements on

the market. On grocery store shelves, everything from orange juice to

bread is " fortified " with it.

 

Packages of antacids, such as Tums and Rolaids, brag about their calcium

content. And no one hypes the health benefits of calcium more than the

dairy industry.

All these products purport to help prevent osteoporosis, the

deterioration of bone mass due to calcium depletion, which afflicts

10 million Americans and causes 1.5 million fractures annually.

 

The specter of spending our senior years stooped over like a question

mark, slowly, carefully and painfully crossing the street with the aid

of a cane or a walker, afraid of sustaining a serious or even fatal

injury from a simple fall, is frightening indeed.

 

It would seem, therefore, that we should all eat as many calcium-rich

foods as possible and take calcium supplements to guard against this

debilitating condition, right?

 

Wrong!

 

At least, not without knowing what we are doing.

 

Studies have shown that those who ingest large quantities of calcium can

also be among the most at " risk " to develop osteoporosis.

The reason for this is that the amount of calcium we ingest does not

necessarily translate into the amount of calcium we " absorb " .

 

At least as important as the amount of calcium in our diet is the " type "

of calcium we eat, and what we eat with it.

 

Certain " cofactors " in proper " proportion " are absolutely necessary for

the body to absorb calcium, while other substances " inhibit " the body's

ability to do so.

 

The amount of gastric hydrochloric acid and the acidity (pH level) of

our bodies is also of fundamental importance.

 

Even our " hormonal balance " plays a key role in calcium metabolism.

 

Without taking all these factors into account, blithely loading up on

calcium can actually result in a net *deficiency* of the mineral.

 

The bones: our blood's *calcium bank* Bone cells are the body's " savings

account " of calcium.

 

When blood levels of calcium rise above normal, the excess is " stored "

in the bones. Conversely, when calcium levels in the bloodstream dip,

the body turns to its bone bank to " balance " the deficit.

 

Our *serum* calcium level is affected by many factors, many of which

are not directly related to the " amount " of calcium in our diets.

 

For example, stress can " reduce " free calcium by disrupting hormone

balance. Stress stimulates the production of the hormone cortisol, which

in turn increases levels of the steroid hormone " aldosterone " , a key

regulator of " mineral balance " in the body.

 

Chronic stress can reduce blood calcium levels, requiring the body to

continually make " withdrawals " from the bone bank.

--

The Dairy myth

--

 

There is no question that we need an adequate dietary intake of

calcium. But how much is adequate? What are the best sources?

 

And what " factors " are necessary to absorb and utilize this calcium and

to maintain proper levels of calcium in both our bones and our

bloodstreams?

 

People " equate " calcium with dairy, and dairy products contribute 75% of

the calcium in American diets. Milk is a $19 billion industry in

the United States, and the Dairy Council spends hundreds of millions

of dollars in advertising and marketing every year.

 

The " Got Milk " ad " campaign " is among the most successful in advertising

history.

However, scientists long have challenged the " assumption " that dairy

" consumption " equals strong bones. Now, thanks to new studies, their

argument is gaining momentum.

 

It's easy to understand why the dairy industry touts milk as the

perfect calcium conveyor.

An eight-ounce glass packs 300 mg of calcium along with magnesium and

phosphorus all cofactors for bone health. Cheese and yogurt are

similarly endowed. But not everyone swallows the idea that a diet

chock-full of dairy is the best way to bank calcium.

 

The dairy industry's armor was badly pierced five years ago by a

Harvard Nurses' Health study published in the American Journal of

Public Health. Researchers examined the diets of 77,761 women during a

12-year period.

 

What they found was that drinking milk did not " protect " the

participants against bone breaks.

 

In fact, those who drank the most milk (three or more glasses a day) had

" more " fractures than those who barely touched the stuff (less than one

glass per week).

 

I'm not surprised that people who consume a lot of dairy don't

necessarily have better bones, says Diane Feskanich, lead author of the

study and an epidemiologist at Brigham and Women's Hospital in Boston.

 

Feskanich is still monitoring the nurses to see how they're

faring, and she hopes to publish more data sometime this year. We

updated the analysis and found the same results:

We don't see fewer hip fractures with higher milk consumption, she says.

 

 

There is definitely a link between " Dairy consumption " and osteoporosis.

 

 

What the Nurses' Health study showed is that, as a preventative

strategy against osteoporosis, eating dairy products is no better

than a placebo, says Neal Barnard, M.D., president of the Physicians

Committee for Responsible Medicine, a nonprofit organization that

promotes vegetarianism and opposes milk consumption.

 

The dairy industry is built on convincing people that it works.

 

A more recent strike against the dairy industry came in the form of a

scientific review published last September in the American Journal of

Clinical Nutrition. Researchers at the University of Alabama gathered

all of the credible clinical evidence they could find on bone health and

dairy-rich diets.

After an exhaustive review of nearly five dozen studies, they concluded

that there is no " solid body " of evidence to support eating dairy foods.

 

 

If dairy foods are so loaded with calcium, why are they not

" protective " of bones?

 

One reason is dairy products' relatively high " protein " and " salt "

content.

The body " utilizes " calcium to " metabolize " both protein and salt.

 

Approximately 1 mg of calcium is needed to " process " 1 g of protein, and

Americans routinely eat 65 to 100 g or more of protein each day.

 

The authors of the study found that some dairy foods, such as cottage

and processed cheeses, are so high in protein and sodium, (which also

acidifies the blood), that the combination could actually " negate " the

food's calcium benefits.

 

That discovery doesn't surprise Loren Cordain, Ph.D., an evolutionary

biologist at Colorado State University in Fort Collins.

[see Cordain's story, A Diet Solution Based on Evolution, March 2002.]

Cordain is one of a growing number of theorists who believe that the

crux of Americans' high rate of osteoporosis is not a " lack " of calcium

but our " Western diet " :

heavy on " acid-inducing " proteins and light on " alkaline-enhancing "

fruits and vegetables.

 

What we're seeing is a calcium imbalance, says Cordain. It's not about

how much " comes in " , it's about how much is *going out*.

 

Americans have the highest rates of osteoporosis-related fractures in

the world, yet we eat " more " dairy products than almost any other

country.

 

The data sticks out like a sore thumb.

 

Indeed, the facts are confounding. People in North America and northern

European nations consume two to three times as much calcium

as their Asian counterparts, yet break two to three times as many

bones.

 

The United States has one of the world's highest recommended daily

allowances for calcium, and it keeps creeping higher.

According to the National Academy of Sciences, which sets the RDA, daily

calcium recommendations start at 1,300 mg for adolescents ages 9 to 18,

then lower to 1,000 mg for adults ages 19 to 50, and, finally, rise

again to 1,200 mg for people 51 and older.

 

Reaching the RDA for calcium is virtually impossible unless you're

eating tons of dairy products, which is precisely the point, says

Cordain. Cordain likes to refer back to the diets of hunter-gatherers

for dietary guidance.

 

He points out that milk is a recent phenomena and that if what dairy

advocates say is true, then everyone living before

the " age of milk " should have had osteoporosis.

 

We don't find that at all, he says. What we do find are robust,

" fracture-resistant " bones.

 

Holistic nutritionists also point out the unnatural aspect of what

was touted by the dairy industry as nature's most perfect food:

No other mammal drinks milk from its mother after it is weaned, and no

other species drinks the milk of another species.

 

Feskanich is also skeptical of the RDA for calcium.

 

Upping the calcium requirements doesn't seem to be helping prevent hip

fractures in America, she says. It's almost as though we keep raising it

in hopes that it will have some effect, and it just doesn't work.

 

So what does all this mean to someone who wants to eat a bone-healthy

diet? The science may be complicated, but the dietary advice is not. Eat

plenty of fruits and vegetables

 

If you find it hard to believe that eating green vegetables is a

superior way to get " adequate calcium " , consider the diet of dairy

cows. These animals maintain their own huge bone structures and

produce calcium-rich milk from a diet of grass.

 

While it's true that, cup for cup, most vegetables have less calcium

than milk, the body is able to " absorb " more of the mineral when it

comes from a " veggie source " , explains Barnard, because it doesn't come

" packaged " with protein and salt.

 

In fact, the body absorbs more calcium from kale and broccoli than from

milk.

A 1997 study published in the New England Journal of Medicine found

that as participants upped their fruit and vegetable intake from 3.6

to 9.5 servings a day, their calcium loss declined 30%.

 

A minimum of five servings of fruits and vegetables a day is important

for bone health because it creates a more " alkaline " environment, and

less calcium is " lost " in the urine, Weaver says.

 

Among the richest sources of plant-based calcium are dark, leafy

greens, such as brussels sprouts, mustard greens, broccoli, turnip

greens and kale.

 

But be aware: Not all calcium-rich veggies translate

that calcium into bone. For example, spinach and sweet potatoes are

loaded with calcium but are " reluctant " to deposit it as they travel

through the body; both are high in oxalate and phytate, two compounds

that inhibit calcium absorption.

 

(However cooking tends to eliminate the " oxalate problem " .)

 

====================================================================

Don't depend on Fortified Foods -

 

When deciding where your calcium should come from, " fortified " foods

belong at the bottom of your list.

 

The vitamins and minerals added to " processed " foods are necessarily the

" cheapest " available, and their

sources and forms are uncertain. Foods that are artificially pumped full

of calcium shouldn't replace " natural " sources.

 

There are so many beneficial factors in food that haven't even been

identified; you really need to go to foods first, says dietician Lola

O'Rourke, a spokesperson for the American Dietetic Association.

===============================================

Watch your salt intake -

 

A " high-sodium " diet drags calcium from bones to " aid " digestion.

 

Every day, the typical American eats 3 to 4 g of sodium, equaling a

daily calcium loss of up to 80 mg.

 

By reducing your daily sodium intake by 1 g, you'll save 1% of your

skeletal mass each year.

 

Be sure to use natural sea salt containing at least 2% trace minerals.

And do your best to avoid sinfully salty snacks, such as potato chips

and microwave popcorn. Give high-sodium, processed foods, such as frozen

dinners, the boot, too.

 

--\

----

 

Trim protein

 

Eating just one meat-free meal a day can reduce your protein intake

by 40 g, meaning that 40 mg of calcium will stay in your bones, where it

 

belongs.

 

Plant-based proteins have the added advantage of containing " fiber " , an

" adequate " supply of which is essential for proper " digestive

functioning " .

 

Calcium is absorbed from the small intestine into the bloodstream, and

the " health " of the " small intestine " directly affects the " amount " of

calcium we " absorb " from our food.

 

===============================================

Shun soda -

 

Last year, scientists at Harvard found that teens quaffing soft

drinks were three times more likely to break a bone than those who

didn't partake. The risk of injury jumped to five times more likely

for girl athletes.

 

Some researchers point to " phosphoric acid " as the culprit since it's

thought to " hamper " calcium absorption.

 

 

Get plenty of vitamin D-

 

Vitamin D must be present in sufficient quantity for your body to

absorb calcium from the intestines into the bloodstream. Be sure to

get outside and get adequate sunlight our bodies synthesize vitamin D

through the action of ultraviolet radiation on " sterols " (fat-like

substances) in the skin.

You can also add vitamin D-rich organic egg yolks and fish oil to your

diet.

 

For adults, the recommended daily allowance for vitamin D is 400 to 600

IU. Many seniors, especially those who are housebound, suffer from a

vitamin D deficiency.

The National Osteoporosis Foundation recommends up to 800 IU per day for

the elderly.

===============================================

Exercise -

 

Bone density rises and falls according to the demands placed upon it, so

 

physical activity has lifelong implications for skeletal health.

 

Adults who were physically active during childhood have better bone

density than those who were couch potatoes. A recent study by

scientists at Pennsylvania State University found that exercise

during the crucial bone-building years is the best predictor of a

woman's adult bone health.

 

Researchers tracked the diets and exercise habits of 81 girls from age

12 to 18. Those girls who saw the greatest bone gains as adults were

those who exercised the most

during their teens, not those who consumed the most calcium.

 

So, boost your bone density by hitting the pavement or the gym.

Experts agree that 30 minutes of weight-bearing exercise, such as

walking or jogging, three times a week is all it takes to see

results. Strength training is also an excellent way to keep bones

strong. Either way, it is never too late to start.

 

In studies that examined physical activity among the elderly, exercise

reduced the risk of bone-breaking falls by 25%. Exercise gives your

bones a reason to live, says Barnard.

 

===============================================

 

Check your stomach acidity

 

Calcium cannot be digested without sufficient stomach acid. It is

estimated that by age 50, most Americans have lost 50% of their " acid-

producing " stomach cells to " protein overload " , parasites, poisonous

substances in food and other factors.

 

Under the best of " circumstances " , only about 30% of the calcium we

ingest is " absorbed " ; without sufficient hydrochloric acid in our

stomachs, this figure can drop as low as 4%.

 

This is also why antacids, which claim to be a calcium source, actually

work " against " calcium absorption.

 

Ironically, many people take these products because they suffer from

heartburn, which they attribute to " excess " stomach acid.

 

Yet, according to gastroenterologist William Stuppy, M.D., the vast

majority of his mature patients suffer from too little stomach acid,

which can produce the same " symptoms " as excess acid.

 

Dr. Stuppy warns especially against taking acid blockers such as Pepcid

AC.

For patients with chronic digestive problems, stomach pH can be

easily measured during routine tests.

One more way to help your stomach is to chew your food well: Food that

is thoroughly masticated generally " requires " less stomach acid to

digest.

 

=====================================================================

 

When it comes to obtaining calcium from food, the options are

plentiful.

 

However, long-term calcium supplementation, particularly without the

other factors necessary for bone health, is not likely to stave off

osteoporosis. And without the advice of a qualified holistic

nutritionist or naturopathic doctor, it is possible to do more harm than

good.

 

The amount of bone-density increase you get from supplementation is

dubious, says Feskanich.

One theory is that it works initially and then plateaus. And there's the

 

issue of consuming " too much " .

Regularly ingesting calcium in excess of 2,000 mg a day may cause

constipation, kidney stones or other problems.

 

Michael Borkin, N.M.D., often puts his patients on a calcium

supplement or, more accurately, supplements.

He recommends rotating the form of calcium, however, between calcium

citrate (one of the easiest forms to absorb), calcium ascorbate and

calcium gluconate.

He also makes sure his patients supplement the necessary cofactors in

proper proportion, including vitamin D and phosphorus.

 

The relationship between calcium and magnesium is a good example of

the complexities of calcium supplementation.

 

Magnesium has an inverse relationship with calcium.

 

Both compete for the same " receptor sites " in cells, but a proper

balance

of both is necessary for health.

 

The ratio can vary considerably from patient to patient.

 

The body can't absorb more than 500 mg of calcium at a time,

so supplements are best taken in small doses throughout the day.

 

Calcium can interfere with some medications, including antibiotics.

So if you're taking a prescription drug, consult your health-care

practitioner before adding a calcium supplement.

 

Contaminants, such as " aluminum " and " lead " , are also a concern with

some OTC calcium tablets (such as Tums).

To find out if a supplement has aluminum, check the list of ingredients

on the label. (Tums Contains Aluminum)

 

Avoid supplements made with bone meal, dolomite or oyster shells, as

they often contain lead.

 

Remember, ingesting more calcium is not necessarily the key to

preventing osteoporosis.

But getting the right calcium may be just what your body needs.

 

Catherine Guthrie's health and medical writing has appeared in Self,

Yoga Journal, Health and on WebMD.

 

=====================================================================

Men, Prostate Cancer and Calcium: A cautionary note

=====================================================================

Calcium is usually talked about in connection with women and

osteoporosis (80% of osteoporosis sufferers are women), but more than a

dozen studies show a link between a " high-calcium " diet and prostate

cancer.

 

In one of the largest, scientists at the Harvard School of

Public Health studied the diets of 20,885 male physicians to tease

out the relationship between dairy products and prostate cancer risk.

 

Their results, published in the October 2001 issue of the American

Journal of Clinical Nutrition, found that men who consumed more than

600 mg of calcium per day had a 32% increased risk of prostate cancer

compared with those who took in less than 150 mg per day.

 

The authors concluded high calcium intake, mainly from dairy products,

may increase prostate cancer risk --

by lowering " concentrations " of 1,

25-dihydroxyvitamin D3, a hormone

thought to protect against prostate cancer.

 

For each additional 500 mg of calcium from dairy products per

day, researchers saw a 16% jump in the men's prostate cancer risk.

 

There's a general message that the more calcium the better, says June

Chan, the study's lead author. That's not necessarily the case,

especially for men. Even more surprising were results from a 1998 study

that traced the health of 50,000 men.

 

The researchers found that those men who were avid calcium consumers

(more than 2,000 mg per day) had a nearly

fourfold increase in the incidence of prostate cancer over their

calcium-shirking counterparts (500 mg or less a day).

 

Should men swear off calcium-rich foods?

Chan says no. She suggests that men are safe to stay within their RDA of

1,200 mg and can avoid

going overboard by taking a hard look at how much calcium they take

in daily,-- adding up the calcium they consume from dairy products,

fortified foods and multivitamins.

 

Don't forget to tally the calcium in antacids;

Chan suspects that an " overdependence " on the stomach-

soothers may be to blame for men's " megadoses " .

 

Other experts aren't so willing to rely on the RDA. Chan's advice is

flat out wrong, says Neal Barnard, M.D. He feels that medical

researchers, like Chan, are simply afraid to take a stand against the

dairy industry.

 

I understand that people hate to make a recommendation against a product

that we've known and loved, but enough is enough, says Barnard.

We can't cut the risk of prostate cancer to zero, but there are things

that help. I think men would be " well-advised " not to drink cow's milk.

==============================================

 

Why We Need Calcium

 

There's no doubt that calcium is crucial to good health. It is the

most abundant mineral in our bodies, making up 1.5% to 2% of our

weight. Ninety-nine percent of this is stored in our bones and teeth;

our bones consist of about 70% calcium salts by weight. Calcium makes

our bones strong and rigid by forming part of the substance that cements

 

together the walls of adjacent cells.

 

But calcium does more than maintain our skeletal structure. It is

essential for the normal functioning of all body cells, acting as a

mediator for many vital cell functions.

 

While our bones contain 99% of our calcium, the remaining 1% of free

calcium circulating in our

soft tissues, bloodstream and extracellular fluid also performs some

crucial functions. For example, without calcium, blood will not clot.

 

Calcium also regulates muscles' contractility and the beating of our

heart.

 

It regulates neurotransmitters at synaptic junctions, where nerve

impulses are passed from one neuron

to another, and calcium disregulation can cause mental and emotional

problems.

 

The body carefully regulates these calcium levels, keeping them

within the range of 50 to 65 mg per liter of extracellular fluid.

More or less than this can quickly lead to serious and even life-

threatening conditions.

 

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