I found your post about calcium absorption from different foods really interesting.
Are there other vitamins or minerals where that happens?
-- Nancy (last name withheld)
Coral Gables, FL
Yes -- let's talk about iron!
The highest iron absorption rate occurs with beef -- of which our bodies absorb approximately 20 percent.
Poultry and pork are relatively close, averaging anywhere from 15 to 18 percent absorption.
When it comes to foods like beans and spinach, though, our bodies only take up 2 percent!
Fish falls somewhere in between -- roughly eight percent of the iron in boiled fish is absorbed, but that figure is slightly increased if you're talking about canned tuna fish.
Remember -- heme iron (found in animal products) is more absorbable than non-heme iron (from plant foods).
Here is some interesting -- and little-known -- iron trivia:
The Dietary Reference Intake for iron is 8 milligrams for adult men ages 19 - 50 and 18 milligrams for adult women in that same age group, but those figures tell very little of the real story.
Truth is, we only need anywhere from 0.5 to 2 milligrams of iron a day.
However, to absorb those amounts, we need to consume anywhere from 8 to 18 milligrams of iron in our food.
Since food labels only display the total iron in a food (rather than what is actually absorbable), the Dietary Reference Intakes take this into account.
More importantly, though, those DRIs are strictly for omnivores.
Vegetarian men ages 19 to 50 should aim for 14 milligrams a day (remember, we are talking total/food label figures here), while women of that same age should be getting 33 milligrams per day!
A vegetarian diet does not in and of itself cause anemia; vegetarians simply need to eat higher amounts of non-heme iron to supply the body with sufficient quantities of this mineral.
March 11, 2009
You Ask, I Answer: Iron Absorption
Labels:
heme iron,
iron,
iron absorption,
non-heme iron,
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1 comment:
Hi Andy. REALLY appreciate your blog.
I recently learned that postmenopausal women require much less iron that others which makes sense. It was discovered that I had a high red-blood cell count. The culprit was my vitamins. I switched to "old lady" vitamins and all is well!
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