Calcium needs for vegans?

[brimstoneSalad]

I had come across it here http://kidneystones.uchicago.edu/citrat ... nt-stones/

Unless unavoidable, a whole food plant based source would probably be better.

Assuming it was citric acid that was beneficial, whole food sources would likely come with a lot of sugar, and promote tooth decay (due to acid exposure).

However, based on my knowledge of chemistry and biology, I think you may have misread that report. They're administering alkaline citrate salts (like potassium citrate) which make it into the bladder to raise pH.

https://en.wikipedia.org/wiki/Potassium_citrate

I'm a little surprised it doesn't disassociate in stomach acid, but maybe due to its high solubility it doesn't have time.

Citric acid on its own shows up free in the blood and is quickly oxidized/metabolized by the vast majority of people, only a fraction of a percent making it into the urine with extremely high doses.
Here's an old study: http://www.jbc.org/content/113/1/265.full.pdf

Calcium citrate has a low solubility, and IIRC would be expected to disassociate in the stomach to neutralize stomach acid. The calcium would become calcium chloride (reacting with the HCl), and the citrate would become free citric acid. Both would ultimately enter the blood, the citrate being metabolized (gone, as if it had never been), and the chloride providing calcium and chloride ions in the blood (for whatever purpose the body would put them).

A biochemist could answer this question better than I can, but I can't see the citrate form being meaningfully different, aside from perhaps that it provides free citrate ions in the stomach that might assist in the chelation of other minerals there (forming Iron citrate, perhaps, or competing with oxalates). In that sense it would be a bit better than a carbonate. I suppose a phosphate would be the least desirable if you have issues with stones.

[garrethdsouza]

I think Jack Norris RD updated his sites. There's a page on oxalate as well now, and yup it does mention calcium citrate in the context of kidney stone treatment etc. And some recommendations in general about preventing stones.

http://www.veganhealth.org/articles/oxalate

[seitan_forker]

I purchased a Calcium + D more for the latter as it's the winter months and I'm usually covered by clothes while outside. Pretty quickly realized I should have went with Vitamin D on it's own as the overabundance of calcium made me constipated, the severity of which was something I had never once experienced as a vegan. Though the connection between the two isn't rock solid (gross pun intended), it hasn't happened again since taking 1 supplement every other day as opposed to the suggested 2 daily.

[garrethdsouza]

Yes, me too! I also started having similar issues when I switched to fortified soymilk when I was on unfortified earlier. Now i just have homemade, additionally since store bought is pretty expensive here.

I also wound up with a (somewhat painful and tiny) kidney stone problem within a couple of weeks of taking a similar calcium-vitamin d supplement, which I've never experienced before. Got resolved on its own after stopping the supplement. Now I just take a d supplement occasionally and try to meet my calcium requirements from food.

[brimstoneSalad]

I think Jack Norris RD updated his sites. There's a page on oxalate as well now, and yup it does mention calcium citrate in the context of kidney stone treatment etc. And some recommendations in general about preventing stones.

http://www.veganhealth.org/articles/oxalate

It makes sense that it would bind oxalate, since it's providing calcium ions to do that job in the stomach (and form insoluble calcium oxalate).

I can't find evidence that much citrate makes it into the urine, but maybe the very minute differences in urinary citrate are meaningful to stone reduction.

[garrethdsouza]

Dr. Gregger has two new videos on calcium supplements and the general advice is to not supplement but try getting it from diet. May also be a reason to avoid fortified soymilk which has calcium added.

https://m.youtube.com/watch?v=KEiUVzCIXJU
https://m.youtube.com/watch?v=OuiGrT6aSvQ

[brimstoneSalad]

Thanks Garreth

Dr. Gregger has two new videos on calcium supplements and the general advice is to not supplement but try getting it from diet. May also be a reason to avoid fortified soymilk which has calcium added.

https://m.youtube.com/watch?v=KEiUVzCIXJU
https://m.youtube.com/watch?v=OuiGrT6aSvQ

Sounds like it's just important to avoid huge amounts of supplementation (most of those studies seemed to deal with a gram or more per day). Small amounts, within the margins that your body can use (or if you're eating a low calcium diet) would probably be taken up.

Based on that, the UK recommendations seem more reasonable. 700 mg a day is much easier to get.
500 mg a day may even be OK, but that's probably pushing it. I would try not to get much less than that. If you are, then a calcium supplement up to 500 mg total calcium a day at least would probably provide benefit. Beyond that, maybe not. Although there may be concern with bio availability for many calcium sources (such as in the presence of oxalates).

At that intake, chickpeas and soybeans are both rich calcium sources, though. So, a diet based around beans, veggies, and limited whole grains (only grains are low in calcium by that metric) should provide enough calcium. Nuts and seeds are also pretty rich sources.

That makes things easier, and it may just mean we have to advise people against eating too many grains unless they supplement a little calcium.

[brimstoneSalad]

New information on Calcium!

https://www.sciencedaily.com/releases/2016/04/160416153144.htm

UK study supports cardiovascular safety of calcium and vitamin D supplementation
No link between calcium supplementation, with or without vitamin D, and hospital admissions or mortality due to cardiovascular events
Date:
April 16, 2016
Source:
International Osteoporosis Foundation
Summary:
Rsearchers have presented a new study that supports the cardiovascular safety of calcium and vitamin D supplementation. The study was based on analysis of the UK Biobank, a very large study comprising 502,664 men and women aged 40-69 years.

Given this, I wouldn't worry about calcium supplementation, even up to a gram. The links to cardiovascular disease are probably due to poor controls (and dairy) in other studies.

[inator]

EDIT (with respect to cardiovascular disease risk):

New information on Calcium!

https://www.sciencedaily.com/releases/2 ... 153144.htm

UK study supports cardiovascular safety of calcium and vitamin D supplementation
No link between calcium supplementation, with or without vitamin D, and hospital admissions or mortality due to cardiovascular events
Date:
April 16, 2016
Source:
International Osteoporosis Foundation
Summary:
Rsearchers have presented a new study that supports the cardiovascular safety of calcium and vitamin D supplementation. The study was based on analysis of the UK Biobank, a very large study comprising 502,664 men and women aged 40-69 years.

Given this, I wouldn't worry about calcium supplementation, even up to a gram. The links to cardiovascular disease are probably due to poor controls (and dairy) in other studies.
(this doesn't apply to risk of stone formation, if there is one from some sources)

Well I can't find the original study to check it in more detail, but it seems to be a population study.

It's an interesting find, but it definitely doesn't negate the results of previous not just observational, but also intervention studies, which suggest that 1.there is a risk of CDV associated with supplements and 2. supplements are not very effective in preventing bone fractures anyway (especially the more serious hip fractures).
At this point we need more intervention studies to draw uncontroversial conclusions - preferably some that control for initial dietary calcium intake + sources.

Obviously I also think that in marginal cases where someone is really far from meeting their calcium needs through diet, a supplement might help. That said, I don't find that getting enough calcium from food is difficult at all and I really doubt that most people (even vegans) have this problem. At least when following European guidelines, not the 1-1,2g recommendation.