Thursday, March 03, 2005

Those Bones, Those Bones, Those Dry Bones1

I used to think when I downed a 500 mg. calcium tablet that my body was getting a 500 mg. dose of calcium. I could feel by bones harden instantly.

And then I learned the truth.

But I'm getting ahead of myself. You see, I'm at an age now where the health of my bones concerns me more than the cut of my hair, the sootiness of my lashes, or the rise of my jeans ... all important considerations at various times in my not-so-distant past. Now it's the bones. Really. My mother moved through middle age amassing a characteristic dowager's hump at the top of her spine. We thought it was endearing. It was ominous.
In the US, 1 in 2 women will suffer a fracture in her lifetime, a direct result of bone loss or osteoporosis.
- National Osteoporosis Foundation
My god, that's a lot of women. Not to sound obtuse, but it's half the women I know!
(The statistic for men is 1 in 4, so not to let them off the hook.)

A fracture later in life takes a long time to mend. If it happens in my back or hip, I'm in bed and out of commission for god knows how long. Call in and pay for the home health aides. And since I can't walk, there'll be weight gain, with its associated hypertension, diabetes, atherosclerosis, and heart disease. Call in and pay for the physicians and pharmaceuticals. Call in and pay for a maid, chef, errand runner, grass cutter ...

Oh geez. Calcium, please.

But 1500 mg. a day? What if I don't drink milk? See these pills? I'd have to take 6 of them a day. Look at the size of these things. You can't tell me that prehistoric man, who laid the evolutionary groundwork for our calcium needs2, extracted, encapsulated, and swallowed this amount of divalent cation. And who's doing the safety research on this stuff?

Here's the curious part ... we're lucky if we absorb 30% of those 1500 mgs.3 If 1500 mg. represents an amount that a middle aged woman would want to make available to her thinning skeleton, then she would need to eat 5000 mg. or 5 g. of calcium a day, assuming a 30% absorption rate. And with the rule of diminishing returns in force (the more we eat, the less we absorb), is it possible that 15,000 mg. a day of calcium, at a more realistic 10% absorption rate, would supply all the bone mortar she needs?

I kid. Still, recommended calcium amounts are getting out of hand.
  • What does it say that 75% of the world's population cannot digest the most concentrated form of calcium, milk?
  • What does it say that women who drink lots of milk increase their risk for ovarian cancer?
  • What does it say that men who consume high levels of calcium increase their risk for prostate cancer?
  • Calcium interferes with the absorption of a litany of other minerals. Am I risking anemia (iron deficiency) or lowered immunity and cancer (zinc deficiency) just so I may continue to haul my withering limbs around on a sturdy skeleton?
  • How about kidney stones?
  • If none of the above causes pause in a calcium popper, the constipation that results is sure to create a league of clandestine Dietary Reference Intake Avoiders.
Researchers are in agreement that a minimum of calcium, around 550 mg/day, is beneficial. But opinions diverge when amounts above 1000 mg. are suggested. And there's no solid evidence that 2 or 3 servings of milk a day reduces the chances of breaking a bone.

Researchers also agree that a shot of vitamin-D-filled sunshine and daily physical activity (including some weight bearing exercise) are some of the best things you can do to protect your skeleton. So for now, I'm ditching these pills for weights. Move over Manang; make room for another amazing dancing laundry folder.


1 Photo of "Skeleton in Forest" compliments of Seth Lew at the Artist Studio.
2 If evolution is just a theory that holds little weight to you, you're welcome to substitute "Intelligent Design" here, although the intelligence of this particular design escapes me.
3 In answer to my initial question ... I absorb between 50 and 150 mg. of that 500 mg. calcium tablet. The rest travels to the landfill by way of American Standard's AquaForce Flushing System.

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