23 replies to this topic

[ta5]

J Urol. 2012 Apr;187(4):1287-92.

Impact of calcium intake and intestinal calcium absorption on kidney stones in older women: the study of osteoporotic fractures.

PURPOSE:

Intestinal calcium absorption is thought to have a critical role in nephrolithiasis. However, to our knowledge no study has directly assessed this association. Therefore, we explored the relationship among intestinal fractional calcium absorption, calcium intake and nephrolithiasis.

MATERIALS AND METHODS:

The Study of Osteoporotic Fractures is a prospective cohort of 9,704 postmenopausal women recruited from population based listings in 1986 and followed for more than 20 years. Secondary analyses were performed of 7,982 women who reported their history of nephrolithiasis, of which 5,452 (68%) underwent an oral radioactive calcium assay (45Ca). The impact of dietary and supplemental calcium on intestinal fractional calcium absorption was evaluated, and factors independently associated with nephrolithiasis were determined.

RESULTS:

Fractional calcium absorption decreased with increased calcium intake, with no difference between dietary and supplemental calcium. Fractional calcium absorption was higher in women with a nephrolithiasis history among all calcium intake groups. Increased dietary calcium intake reduced the likelihood of nephrolithiasis by 45% to 54% (p=0.03). Women with a history of nephrolithiasis were less likely to supplement calcium (p<0.001). In adjusted analyses women who supplemented calcium were 21% to 38% less likely to have a nephrolithiasis history (p=0.007) and there was a 24% increased risk of kidney stones for each 10% increase in fractional calcium absorption (p=0.008).

CONCLUSIONS:

Fractional calcium absorption is higher in women with a history of nephrolithiasis. Higher intestinal fractional calcium absorption is associated with a greater risk of historical nephrolithiasis. Dietary and supplemental calcium decrease fractional calcium absorption, and may protect against nephrolithiasis.

PMID: 22341269

 

 

From the full text, they offer this explanation: 

Thus, similar to previous studies, limited dietary calcium intake may predispose women to nephrolithiasis.19, 20 This may be due to a lower concentration of calcium in the intestinal tract to bind oxalate, increasing intestinal oxalate absorption and subsequent excretion in the urine. Previous studies have reported more than a 50% decrease in the development of nephrolithiasis for women consuming the highest amounts of dietary calcium, after adjustment for known nephrolithiasis risk factors.18–20 It is likely that increased dietary calcium intake is associated with greater intake of unrecognized factors which protect against kidney stone formation.21

 

[...]

 

Thus it is likely that an elevated fractional calcium absorption would leave less intestinal calcium available to bind oxalate, thus increasing oxalate absorption and urinary oxalate excretion. Dietary and supplemental calcium decrease fractional calcium absorption, and this may partially protect women from the subsequent risk of kidney stones.

 

 

 

Edited by ta5, 30 May 2014 - 07:39 PM.

[Luminosity]

Please explain this in plain language. I don't understand what they are trying to say.

 

I'm concerned that people will up their calcium supplementations based on your headline, or start taking calcium supplements.  

 

My understanding of that is that, although we need calcium, calcium supplements are difficult to break down.  They can lead to kidney stones, calcifications, plaques in arteries and bone spurs. The higher the dose, the more likely.   Personally I just take calcium from food sources.  

Edited by Luminosity, 31 May 2014 - 06:21 AM.

[rwac]

Essentially increased calcium intake is associated with a reduced chance of kidney stones.

 

Probably via the parathyroid. Low calcium intake is paradoxically associated with high serum calcium because the parathyroid (PTH) can dump a lot of calcium from the bones. And high serum calcium causes kidney stones.

 

Sometimes simplest is best, as in eggshell or oyster shell calcium.

[ta5]

When I first read this, I was surprised too. I seriously thought I didn't understand what they meant by the term "fractional calcium absorption". It's just the obvious definition. 

 

Here's another study with full text that talks about the study above (reference 66).:

A recent study by Sorensen and colleagues66 evaluated a cohort of nearly 10,000 women followed for 20 years who were administered radioactive oral calcium assays. The impact of dietary and supplemental calcium on intestinal fractional calcium absorption and the development of urinary stone disease was determined within the cohort. Fractional calcium absorption was found to be associated with increased risk of stone formation; however, it decreased with increased dietary calcium intake. As a result, increased intake of calcium decreased the likelihood of nephrolithiasis. The effect was noted to be a decrease of at least 45% for all levels of dietary calcium intake compared with patients in the lowest quintile of intake. This observation was thought to be from active absorption of intestinal calcium at low calcium intakes compared with passive paracellular diffusion of calcium at higher intake levels, which tends to be more linear.67 With decreased intestinal calcium to bind to oxalate in the gut of these individuals, the oxalate is absorbed and ultimately excreted in greater concentration into the already hypercalciuric urine, increasing the likelihood for calcium oxalate stone formation.66

 

This understanding of the pathogenesis of urinary stones is not only important for this disease process but also has important implications in other disease processes. For example, several epidemiologic studies have noted an increased risk of osteoporotic fractures in patients with urinary stone disease.68–70 This association is thought to be related to multiple risk factors, including metabolic acidosis, mutual genetic factors, and abnormal bone remodeling in hypercalciuric stone formers thought to be from elevated vitamin D levels and aberrant local cytokine and growth factor signals seen in both of these patient populations.68 Sorensen and colleagues66 in their study noted that women with a history of nephrolithiasis were less likely to supplement calcium in their diet, and those who did, did so at low doses. Given that low dietary calcium is associated with osteoporotic fracture risk,71 this suggests that another simple and modifiable reason for the association between urolithiasis and osteoporotic fractures is low calcium intake by stone formers. Although the influence of calcium intake on urinary stone formation is still a subject of debate, based on these data, the authors do not recommend the restriction of dietary calcium supplementation, because no clear increased risk for urinary stones has been shown. However, calcium supplementation is important for reducing the risk of osteoporotic fracture and for maintaining bone health.72,73

 

 

[Luminosity]

Thanks.  Some people might not be able to absorb non-edible animal sources of calcium, though. 

[rwac]

Calcium carbonate is as absorbable as citrate.

 

http://www.ncbi.nlm..../pubmed/9184261

 

Gastric acidity (or the lack thereof) also doesn't affect calcium absorption from calcium carbonate or citrate.

 

http://www.ncbi.nlm....cles/PMC425063/

[Luminosity]

I can't absorb calcium citrate, or any calcium supplement I've tried.  

[rwac]

Have you tried eggshell calcium?

Oyster shell should work too, but "calcium carbonate" doesn't work for me.

 

Industrial citrate can be an irritant.

[misterE]

 Low calcium intake is paradoxically associated with high serum calcium because the parathyroid (PTH) can dump a lot of calcium from the bones.

 

I think you are right rwac. Increased calcium intake lowers PTH, which decreases the amount of calcium being yanked out of the bones and into the blood. It's part of the body's counter-regulatory system. Would you agree that the same phenomena happens with blood-sugar levels, and that eating lots of carbohydrates lowers blood-sugar by lowering glucocorticoids?

[rwac]

 

I think you are right rwac. Increased calcium intake lowers PTH, which decreases the amount of calcium being yanked out of the bones and into the blood. It's part of the body's counter-regulatory system. Would you agree that the same phenomena happens with blood-sugar levels, and that eating lots of carbohydrates lowers blood-sugar by lowering glucocorticoids?

 

This is completely offtopic, but yes, I agree with you there. Diabetes has also been linked to elevated PTH.

 

http://www.diapedia....abetes-mellitus

[misterE]

 Diabetes has also been linked to elevated PTH.

 

 

 

Yes. And this is probably one of the main mechanisms of why vitamin-D is protective against diabetes, because vitamin-D also lowers PTH.

Edited by misterE, 05 June 2014 - 04:30 AM.

[Luminosity]

Tried Jarrow Bone Up which has cow bone calcium, as well as a Chinese Medical formula which contained oyster shell, as well as I think, calcium citrate.  The last was probably a good brand.  They all gave me bone spurs.  I also tried some black mineral water fortified with volcanic minerals, same thing.  Mineral water can give me fibromyalgia.  I tried some good magnesium supplements but they gave me fibromyalgia.  I have been able to take Chinese Medical herbal formulas that are high in iron, as well as black strap molasses for the iron.  I can take carefully take bamboo extract for the silica.

 

Are there plant sourced supplements of calcium and magnesium?  Carrot crystals?  

 

Are there supplements made of black strap molasses with the sugar removed?   

[rwac]

Tried Jarrow Bone Up which has cow bone calcium, as well as a Chinese Medical formula which contained oyster shell, as well as I think, calcium citrate.  The last was probably a good brand.  They all gave me bone spurs.  I also tried some black mineral water fortified with volcanic minerals, same thing.  Mineral water can give me fibromyalgia.  I tried some good magnesium supplements but they gave me fibromyalgia.  I have been able to take Chinese Medical herbal formulas that are high in iron, as well as black strap molasses for the iron.  I can take carefully take bamboo extract for the silica.

 

Are there plant sourced supplements of calcium and magnesium?  Carrot crystals?  

 

Are there supplements made of black strap molasses with the sugar removed?   

 

Bone calcium is hydroxyapatite which isn't quite the same as carbonate, it's not as good either.
About the bone spurs, one possibility is that you have high estrogen, which isn't always detectable on blood tests.

Have you tested your PTH, it should be low if you're getting adequate calcium and vitamin D.

[Luminosity]

Thanks for the feedback.   Not sure what PTH is.  I don't go to doctors.  Bone Up was the hydroxyapatite stuff.  I've been exposed to calcium carbonate before.  It's often used to "fortify" foods like Quaker Oats, and it's in mineral water and multivitamins.  It doesn't seem to agree with me. I believe that eggshells contain calcium carbonate. I think that it says that on the Swanson's listing for their eggshell supplement.  I haven't tried eggshell calcium specifically.  I think the oyster shell probably contained calcium carbonate?  

 

PTH= Pituitary Thyroid Hormone?  I take a good D and it seems adequate.  I eat natural plain whole milk yogurt.  I eat steamed green veggies.  I drink carrot juice.  I eat almonds.  I sometimes eat a fermented food that is very high in bioavailable calcium.  I feel I could still use magnesium and calcium supplements but I haven't found the right ones yet.  I guess they may be plant-sourced.

 

Due to factors beyond my control there's been a lot of life circumstances that have probably messed with my thyroid. I'm trying to deal with that the best I can.    

Edited by Luminosity, 13 June 2014 - 05:50 AM.

[rwac]

Thanks for the feedback.   Not sure what PTH is.  I don't go to doctors.  Bone Up was the hydroxyapatite stuff.  I've been exposed to calcium carbonate before.  It's often used to "fortify" foods like Quaker Oats, and it's in mineral water and multivitamins.  It doesn't seem to agree with me. I believe that eggshells contain calcium carbonate. I think that it says that on the Swanson's listing for their eggshell supplement.  I haven't tried eggshell calcium specifically.  I think the oyster shell probably contained calcium carbonate?  

 

PTH= Pituitary Thyroid Hormone?  I take a good D and it seems adequate.  I eat natural plain whole milk yogurt.  I eat steamed green veggies.  I drink carrot juice.  I eat almonds.  I sometimes eat a fermented food that is very high in bioavailable calcium.  I feel I could still use magnesium and calcium supplements but I haven't found the right ones yet.  I guess they may be plant-sourced.

 

Due to factors beyond my control there's been a lot of life circumstances that have probably messed with my thyroid. I'm trying to deal with that the best I can.    

 

PTH= parathyroid hormone.

Excess PTH will dump calcium from the bone, it's also inflammatory and leads to high serum calcium .

Vit D and calcium will suppress PTH.

 

So it's probably worth testing for. Also, you can get blood tests without going to a doc.

 

Yes, oyster shell is calcium carbonate.

Edited by rwac, 13 June 2014 - 09:22 AM.

[Luminosity]

Thanks.  I should probably try harder to get a calcium supplement in that case cause I might have that problem.  Again, anyone know of plant-based calcium or magnesium supplements?  Carrot crystals?    

Edited by Luminosity, 14 June 2014 - 06:29 AM.

[rwac]

I know that coffee and chocolate are decent sources of magnesium.

 

Carrot crystals bring with it too much of beta carotene. You might have an excess if your corns are turning orange.

 

Kale(low oxalate) broth might be a source of minerals, but I don't know if it contains much calcium.

Kale itself has anti-thyroid substances, so it isn't that great to eat.

[Luminosity]

Thanks. 

 

I'm pretty mystified by the Kale people.  Kale smoothies? 

Edited by Luminosity, 15 June 2014 - 03:22 AM.

[MrHappy]

Thanks. I should probably try harder to get a calcium supplement in that case cause I might have that problem. Again, anyone know of plant-based calcium or magnesium supplements? Carrot crystals?

I'd recommend this:
http://www.lifestrea...roducts/calcium

It's the most bio-absorbable I've come across and contains a good set of cofactors, naturally.

I'd keep an eye on your magnesium levels, too. Insufficient magnesium leads to calcium ending up in unwanted places / tissues and not where it's needed.

[Luminosity]

Thanks.  I'm also looking for a magnesium supplement that I can absorb.

 

I can't find a list of the ingredients for the product you linked to.  It also lists "elemental calcium" which scares me because it could be a non-organic source. The other minerals might be problematic because they might not be absorbable or might be not be sourced from edible organic sources.  The seaweed-sourced calcium sounds interesting but I would like to find it alone in a powder, or capsule. 

[MrHappy]

It's entirely powdered sea-vegetable. I use it.

There is some detail on the linked page about it:

Lifestream Natural Calcium is produced from a certified organic sea vegetable called Lithothamnium calcareum...

Lifestream Natural Calcium has a unique porous ‘honeycomb-like’ structure which reacts particularly well in the digestive system and gives it high absorption properties.
A Lifestream Natural Calcium molecule has a very large surface area. This allows faster solubilisation and rapid ionisation of the calcium.
Lifestream Natural Calcium also contains other important minerals necessary for the absorption of calcium including magnesium, boron, selenium, zinc, copper and iodine.

A study comparing the bioavailability of Lithothamnium calcareum (the ingredient in Lifestream Natural Calcium) versus calcium carbonate revealed a higher degree of bioavailability for Lithothamnium than calcium carbonate. The results indicated a significantly higher calciuric response for Lithothamnium than the calcium carbonate and therefore demonstrated greater bioavailability. Further to this, those women who had consumed Lithothamnium experienced a more prolonged decline in serum parathyroid hormone (PTH) levels. Since PTH increases as calcium drops in the blood, the researchers concluded that Lithothamnium suppresses this response for longer and is a further indication of increased bioavailability.

[Luminosity]

Thanks for the clarification.  Do you now how they process it, if they do and how they tablet it?  Is it high in iodine?  I Can only take so much seaweed normally.  

[MrHappy]

It's a powder. Not sure on the manufacturing process, but I'll take a photo of the bottle when I get home.

[Luminosity]

Thank you for your help.