Calcium absorption

About specific vitamines, minerals or fiber, for example
overkees
Posts: 598
Joined: Fri 05 Aug 2011 14:20

Calcium absorption

Postby overkees » Tue 18 Dec 2012 15:49

RRM wrote:That is not the way it works on this forum.
You can make bold statements, but you need to back them up,
or admit you were making assumptions.
Calcium from plant sources is much better than from milk and more bio available.
Please supply a reference, take it back, or admit its just an assumption.
Okay, take kale for example: http://www.all-creatures.org/fact/fact-20080509.pdf
Results
Fractional absorption of milk calcium was 0.321 ± 0.089 (i
± SD) and fractional absorption of calcium from kale was
0.409 ± 0. 101 . Absorption of kale calcium was excellent in all
1 1 subjects, with no value being < 30%. In 9 ofthe 1 1 subjects
kale calcium absorbability was higher than milk calcium. The
mean within-subject difference was 0.088 ± 0.033 (i ± SEM;
P < 0.025).
overkees
Posts: 598
Joined: Fri 05 Aug 2011 14:20

Re: Diet diary

Postby overkees » Tue 18 Dec 2012 16:21

Moreover:
Due to the high protein content of milk, your body needs to compensate this acidicity.
http://www.vivalis.si/uploads/datoteke//2a02.pdf
CONCLUSION:
Consumption of an LCHP diet for 6 weeks delivers a marked acid load to the kidney, increases the risk for stone formation, decreases estimated calcium balance, and may increase the risk for bone loss.
That is why the calcium content in milk is even more less useful than plant sources of calcium. Next to bioavailabillity of the absorption.

What I also find very confusing is that most research leads to thinking that Calcium intake must have been even higher then it is suggested today http://www.altmedrev.com/publications/4/2/74.pdf:
Calcium and The Paleolithic Diet:
The anthropological approach to nutritional needs has received attention lately due to the popularity of the “Paleolithic Diet” concept. This theory asserts that calcium played a major role in the evolution of mammals, of primates and, for the last 35,000 years, of Homo sapiens. This latter period was the last time the human gene pool was able to evolve as a result of human interaction with the environment. The anthropological approach says, with the exception of a few small changes related to genetic blood diseases, that humans are basically identical biologically and medically to the huntergatherers of the late Paleolithic Era.
During this period, calcium content of the diet was much higher than it is currently. Depending on the ratio of animal to plant foods, calcium intake could have exceeded 2000 mg per day. Calcium was largely derived from wild plants, which had a very high calcium content; animal protein played a small role, and the use of dairy products did not come into play until the Agricultural Age 10,000 years ago. Compared to the current intake of approximately 500 mg per day for women age 20 and over in the United States, hunter-gatherers had a significantly higher calcium intake and apparently much stronger bones. As late as 12,000 years ago, Stone Age hunters had an average of 17-percent more bone density (as measured by humeral cortical thickness). Bone density also appeared to be stable over time with an apparent absence of osteoporosis. With the advent of the Agricultural Age, low-calcium, highphosphorus cereal grains replaced high-calcium wild plant foods and calcium intakes dropped (uncultivated plants have approximately four times the calcium of cereal grains).Bone densities decreased in the agricultural age and the incidence of osteoporosis increased in both the Near East and the Americas.
The only hunter-gatherers that seemed to fall prey to bone loss were the aboriginal Inuit (Eskimos). Although their physical activity level was high, their osteoporosis incidence exceeded even present-day levels in the United States. The Inuit diet was high in phosphorus and protein and low in calcium.
It appears that the Paleolithic diet was a very calcium-rich diet. The physiology of those who consumed it adapted to that diet.Today, the intestinal tract does not have effective absorption mechanisms for calcium. It actually may be that in a high-calcium environment, the evolutionary necessity for an absorption barrier for calcium existed. Contrasted with sodium, which is absorbed with 100-percent efficiency, typical calcium absorption averages 25-35 percent at median intakes, and only 50 percent at very low calcium intakes. Net calcium accumulation in present day humans is only 4-8 percent because of renal, fecal, and perspiration losses.
About 150 mg/day of calcium is excreted via digestive secretions, no matter what our intake, whereas sodium excretion in sweat can be reduced drastically if dietary levels are low.If estimated dietary levels of sodium in the Paleolithic diet were a fraction of current intake, sodium physiology might also reflect adaptation. As a result of physiological inability to hold on to calcium and absorption difficulties that arise with age, negative calcium balances may be common.
Also a very interesting read: http://ajcn.nutrition.org/content/54/1/281S.full.pdf please read it.
RRM wrote:That is not the way it works on this forum.
You can make bold statements, but you need to back them up,
or admit you were making assumptions.
RRM wrote: An approximate is good enough,
because (certainly in the case of calcium) the body is very good at adapting the absorption rate.
This absorption rate may be adjusted multiple fold,
so that it generally sufficiently compensates for varieties in nutrient composition..
Please give your references

But what it all boils down to: the main reason how this acidicity relates to health is due to the fact that your body WILL eliminate CO2 from the body as it is acidic for the blood. The decrease in CO2 will cause all the additional health troubles associated with hyperventilating. Hyperventilating will cause this CO2 drop. And voilá there you have it. The circle is round. Please study the buteyko technique, RRM.
User avatar
RRM
Administrator
Posts: 8152
Joined: Sat 16 Jul 2005 00:01
Contact:

Re: Diet diary

Postby RRM » Wed 19 Dec 2012 12:09

overkees wrote:
RRM wrote:
overkees wrote: Calcium from plant sources is much better than from milk and more bio available.
Please supply a reference, take it back, or admit its just an assumption.
Okay, take kale for example: http://www.all-creatures.org/fact/fact-20080509.pdf
You wrote "plant sources".
Kale is an example of plants with a great calcium absorption rate.
In the very study that you quote it says:
"In contrast with the poor absorption previously reported for spinach calcium, kale, a low-oxalate vegetable, exhibits excellent absorbability for its calcium".
So, by presenting only kale as a good source, this is in no way backing up your statement about plant sources in general.
Just the low-oxalate ones (brassica veggies).
"Calcium bioavailability was nearly 10 times greater for low oxalate kale, than from spinach (high in oxalates)" Weaver CM et al

Besides oxalic acid, fiber also plays a role:
"The apparent availability of Cu, Fe, Ca, P and protein were lower when the fiber-containing diets were fed compared to the control diet." Ward AT

And lactose also plays a role, as lactose increases the absorption rate:
"Fractional and total calcium absorption was significantly greater from the lactose-containing formula than from the lactose-free formula" Abrams SA et al

Phytic acid is another inhibitor in plants (and nuts etc):
"Fractional calcium absorption from the high-phytate soybeans averaged 0.310; from the low phytate soybeans, 0.414 +/- 0.074; and from milk, 0.377" Heaney RP et al

and another one:
overkees wrote:
RRM wrote:
overkees wrote:It helped me to restore my teeth almost completely
Drinking milk would help in that case... :)
Milk is very acidifying for the teeth in the end.
Casein phosphopeptides (from milk) have been shown to be anticariogenic; remineralizing enamel Gurunathan D et al Reynolds EC
and contribute to the high bioavailability of calcium from milk, which shows when added to other (plant) foods:
"The addition of casein phosphopeptides improved calcium (15.8 to 17.6%) and zinc absorption from rice-based cereal" Hansen M et al
overkees wrote:Due to the high protein content of milk, your body needs to compensate this acidicity.
For this, its has the bicarbonate buffering system.
"a diet high in protein increases the fractional absorption of dietary Ca" Cao JJ et al
which may be due to the increase of potassium bicarbonate associated with an increase in dietary protein:
"potassium bicarbonate was also associated with higher fractional calcium absorption" Ceglia L et al
So, the acidic influence of high protein does not have a negative impact on calcium absorption, at all, but the opposite,
which makes sense, because you may need more calcium-carbonate for buffering.
Hence the higher calcium absorption rate.
overkees wrote: Calcium from plant sources is much better than from milk and more bio available.
Thats simply nonsense, as studies show.
"Fractional calcium absorption was 0.391 from winged beans, 0.476 from ivy gourd, and 0.552 from milk.
Calcium bioavailability of these 2 vegetables was 71% compared to 86% of milk
Charoenkiatkul S et al

"The mean hourly fractional calcium absorption from fortified soymilk (0.65) was found to be comparable to that of cows' milk: 0.66" Tang AL et al

"Mean percentage absorption was 45.5% from the skimmed milk, 35.7% from the Ca-enriched milk and 27.4% from the watercress soup." Fairweather-Tait SJ et al
User avatar
RRM
Administrator
Posts: 8152
Joined: Sat 16 Jul 2005 00:01
Contact:

Re: Diet diary

Postby RRM » Wed 19 Dec 2012 12:28

That is why the calcium content in milk is even more less useful than plant sources of calcium. Next to bioavailabillity of the absorption.
If that is true, how is it possible that bone mineral density in western countries is greatest?
In western countries, the ratio of plant foods relative to animal foods is smallest.
Also, the intake of milk products is greatest in western countries.
So, its not about the calcium in milk not being useful,
after all, it needs to supply calves with sufficient calcium for rapid bone development.
No doubt that this is succesful.
Consuming milk products is effective in increasing bone mineral density in humans,
and thus its calcium is useful in humans.
What causes osteoporosis is a very different question.
overkees wrote:What I also find very confusing is that most research leads to thinking that Calcium intake must have been even higher then it is suggested today http://www.altmedrev.com/publications/4/2/74.pdf:
Thats just speculation.
We dont know exactly what plants/fruits (oxalic acid, phytic acid etc) / animal foods we ate, and in what proportions,
which will have been very different for different periods and different places / regions of the world.
Bone density also appeared to be stable over time with an apparent absence of osteoporosis.
Osteoporosis is particularly a disease of the elderly.
Who says that these humans ever reached the age of 70 years old?
Bone densities decreased in the agricultural age and the incidence of osteoporosis increased in both the Near East and the Americas.
Osteoporosis is most prevalent in countries with the highest average bone mineral density.
Today, the intestinal tract does not have effective absorption mechanisms for calcium
Not true, the higher the calcium intake, the lower the absorption rate.

"The effect of supplementing a basal diet containing 697 mg calcium daily with an additional 900 mg Ca daily from milk, Ca chloride, or a Ca carbonate preparation was examined in eight adult males during a 56-d metabolic balance study. The ingestion of the milk or Ca supplements had no overall effect on Ca retention by these subjects because the milk and supplements depressed apparent absorption of Ca in the gut and fractional tubular reabsorption of Ca in the kidneys." Lweis NM et al

"During a low calcium intake, fractional calcium absorption was significantly greater (0.582 compared with 0.260) and urinary calcium excretion was significantly lower (1.30 compared with 3.08) than values obtained during a high calcium intake"
...
"These results suggest that during short periods of inadequate calcium intake, girls are able to significantly increase the efficiency of calcium absorption and decrease urinary calcium losses to conserve calcium required for bone mineral acquisition".
O'Brien KO et al
typical calcium absorption averages 25-35 percent at median intakes, and only 50 percent at very low calcium intakes.
Not true, calcium absorption rates may be much higher.
"Fractional 45Ca absorption was approximately 61% in all 3 groups when the diet was unmodified and increased to 71%, 69%, and 68% in the osteoporotic subjects, age-matched control women, and young women, respectively, when dietary calcium was reduced to 300 mg/d."
...
"In contrast, supplementation with 1200 mg Ca resulted in decreased fractional 45Ca absorption, suggesting that the increased calcium intake was associated with a potent compensatory ability of the intestine and calcitropic hormones to adapt.
" Kung AW et al

Thats is also why high calcium supplemenation is useless:
"The mechanisms regulating fractional calcium absorption as a function of intake suggest that very high daily doses are probably useless" Celotti F et al

Even when supplementing with only 300 mg / day, the absorption rate will decrease:
"After 6 months, true fractional Ca absorption of the study group (55.6)%) was significantly lower than that of the controls (64.3%)." Lee WT et al
Contrasted with sodium, which is absorbed with 100-percent efficiency, typical calcium absorption averages 25-35 percent at median intakes, and only 50 percent at very low calcium intakes. Net calcium accumulation in present day humans is only 4-8 percent because of renal, fecal, and perspiration losses.
Maybe there is a reason why net calcium accumulation is only 4-8%.
That reason is the differences in requirements, excretion rates and in 'safe deposits'.
The adjustment of calcium absorption/excretion rates (in response to exposure) is less linear than sodium absorption/excretion rates,
which is due to the presence of a large calcium reservoir: the bones, serving as a buffering system against
too low and too high serum calcium.
In times of high-calcium exposure, calcium may be stored for times of less calcium-exposure.
The downside of this system is the current constant overexposure of calcium,
which induces a contineous storage and deportation of calcium into and from the bones,
eventually exhausting osteoblasts, causing osteoporosis.
overkees
Posts: 598
Joined: Fri 05 Aug 2011 14:20

Re: Calcium absorption

Postby overkees » Wed 19 Dec 2012 17:03

http://onlinelibrary.wiley.com/doi/10.1 ... x/abstract
The test load of calcium was about 83 mg for each source. Fractional calcium absorption from broccoli averaged 0.478 ± 0.089, from bok choy stems, 0.519 ± 0.089, from bok choy leaves, 0.520 ± 0.074, and from kale 0.527 ± 0.091. These differences were both absolutely small and statistically insignificant. Mean absorbability of milk calcium ingested at the same load has been previously shown to be 0.463 ± .095.
But this is not all. No, there is more:

http://ajcn.nutrition.org/content/59/5/1238S.full.pdf
fractional absorption[/u]
Milk 32.1
Almonds, dry roasted 21.2
Beans, pinto 17.0
Beans, red 17.0
Beans, white 17.0
Broccoli 52.6
Brussel sprouts 63.8
Cabbage. Chinese 53.8
Cabbage, green 64.9
Cauliflower 68.6
Kale 27.6
Kohlrabi 67.0
Mustard greens 72 64 57.8
Radish SO 74.4
Rutabaga 61.4
Sesame seeds, no hulls 20.8
Soy milk 3 1
Spinach 5.1
Tofu,calciumset 31.0
Turnip greens 51.6
Watercress 67.0

So, we can conclude that probably the calcium in fruits might be even better absorbable.
User avatar
RRM
Administrator
Posts: 8152
Joined: Sat 16 Jul 2005 00:01
Contact:

Re: Calcium absorption

Postby RRM » Thu 20 Dec 2012 01:21

overkees wrote:But this is not all. No, there is more:
http://ajcn.nutrition.org/content/59/5/1238S.full.pdf
The list that you posted is taken from that one study (study 2), but the actual data are from various studies,
in different subject groups, and therefore not comparable. These groups include vegans and lacto-vegetarians,
and particularly the vegans will have a relatively high fractional calcium absorption,
as their total calcium intake will normally be relatively low.
The authors of this study assumed that fractional calcium absorption is only dependent on calcium load (in the test),
and calculated values from there.
Fractional calcium absorption from milk might also have been 60%, if those vegans would have consumed that milk.
From the studies that i have posted, you can see that this fraction may be that high for milk,
depending on how much calcium is normally consumed by that group of persons.
If you want to compare data, they need to be from the same study, from the same subjects,
as what i did when i posted comparative data. Otherwise its not science, or bad science.
The test load of calcium was about 83 mg for each source. Fractional calcium absorption from broccoli averaged 0.478 ± 0.089, from bok choy stems, 0.519 ± 0.089, from bok choy leaves, 0.520 ± 0.074, and from kale 0.527 ± 0.091. These differences were both absolutely small and statistically insignificant. Mean absorbability of milk calcium ingested at the same load has been previously shown to be 0.463 ± .095.
This (study 1) is also not the right way.
The milk calcium absorbability had not been measured in the same study (same subjects)
Absorbability of ingested calcium does not just depend on load,
but also on how much calcium these persons normally absorb
(as it strongly influences how much calcium the body wants to absorb).

Just take a look at the difference between broccoli and milk in study 1:
broccoli 47.8% vs milk 46.3% ("absolutely small and statistically insignificant difference")
compared to study 2:
broccoli 52.6% vs milk 32.1%
So, from study 1 it appears that the fractional calcium uptake from broccoli is 3.2% higher than from milk,
from study 2 it appears that the fractional calcium uptake from broccoli is 63.9% higher than from milk.....
If the studies had been done properly, no such big difference would have been possible.
overkees wrote:So, we can conclude that probably the calcium in fruits might be even better absorbable.
No, we cannot.
We need data for that.
but at least we can conclude that this is not true:
overkees wrote:Calcium from plant sources is much better than from milk and more bio available.
From the conclusion in study 2:
"vegans are at increased risk of not meeting their calcium needs, especially
during the rapid growth phase. Without the use of supplements
or calcium-fortified juices or soy milk, careful planning is
required to ensure adequate calcium intake from vegetables".


"Milk consumption, preferably to other calcium sources, is associated with lumbar BMC and BMD in postmenarcheal girls." Esterie L et al

Who is online

Users browsing this forum: No registered users and 2 guests