The Straight Dope

Go Back   Straight Dope Message Board > Main > General Questions

Reply
 
Thread Tools Display Modes
  #1  
Old 06-25-2012, 09:47 PM
posskb posskb is offline
Guest
 
Join Date: Jun 2008
Is dolomite limestone safe to use as a supplement?

It is made of calcium and magnesium in close to equal amounts but is it safe to use as a supplement?

Thank you...
Reply With Quote
Advertisements  
  #2  
Old 06-25-2012, 10:01 PM
njtt njtt is online now
Guest
 
Join Date: Jul 2004
I take it that you mean a dietary supplement.

Unless you ground it up to a fine powder, I doubt whether you would digest much of it, and undigested lumps of it might injure your gastrointestinal tract.

The body needs quite a lot of calcium, and some people do need to take calcium supplements. However, it needs only a small amount of magnesium, and most people will get all they need from regular food. Taking a regular calcium supplement this way could cause you to be taking too much magnesium. (I do not know if that can be dangerous, but I would rule out the possibility.)

Any given lump of dolomite might well have traces of other minerals mixed up in it, which could be toxic.

Why would you want to do this? Calcium carbonate supplements are cheap and safe.
Reply With Quote
  #3  
Old 06-25-2012, 10:02 PM
Dallas Jones Dallas Jones is offline
Guest
 
Join Date: Apr 2008
It's clay. Dirt.
Reply With Quote
  #4  
Old 06-25-2012, 10:03 PM
Michael63129 Michael63129 is offline
Guest
 
Join Date: Jan 2012
Many calcium supplements are in fact derived from limestone, or calcium carbonate, so it would seem that it is safe. However, studies have linked calcium supplements to increased risk of cardiovascular disease, despite many people being deficient in calcium (apparently, your body doesn't process calcium carbonate or the other forms used in supplements in the same way as calcium in food). That aside, calcium carbonate isn't as easily absorbed as calcium citrate and other alternatives used in supplements. I'd say drink milk and eat dairy instead if you want more calcium in your diet, unless you are lactose intolerant/allergic to milk or a vegan (I easily consume enough calcium myself this way, plus it is a good source of vitamins A and D, the latter another major nutrient that many people are deficient in).
Reply With Quote
  #5  
Old 06-25-2012, 10:21 PM
posskb posskb is offline
Guest
 
Join Date: Jun 2008
Thank you for the responses. Calcium supplements are not that cheap for me and I can use a 50 pound bag of dolomitic limestone for a lifetime for a small sum. I can't remember how much my garden ferilizer bag cost exactly but I take a pinch of pebbles every day or 2. I worry about impurities but I have not been grinding them up so I may not have been absorbing them anyway. I eat kefir each day or 2 but I wanted a source of magnesium because of constipation. Can epson salt be consumed safely? Thank you...
Reply With Quote
  #6  
Old 06-25-2012, 10:22 PM
Surreal Surreal is offline
Guest
 
Join Date: Mar 2002
Quote:
Originally Posted by njtt View Post
However, it needs only a small amount of magnesium, and most people will get all they need from regular food.
Cite?
Reply With Quote
  #7  
Old 06-25-2012, 10:34 PM
GreasyJack GreasyJack is online now
Guest
 
Join Date: Feb 2008
This might be a bit of geologic pedantry, but dolomitic limestone doesn't contain magnesium and calcium in equal parts. Dolomitic limestone is limestone that contains some dolomite, but less than 50%. If it has more than 50%, it's called dolostone.

Dolostone would only contain exactly 50/50% Ca and Mg if it's 100% dolomite-- if we're talking about a 50% calcite (CaCo3) and 50% dolomite (CaMgCo3) rock, you would be looking at 66% calcium, 33% magnesium. Most dolomitic limestones, however, don't have even that much-- just a trace of dolomite is enough to get it classified as dolomitic and, at least in the regions I'm familiar with, most dolomitic limestone has very low actual dolomite content.

Although if the other posters are correct that you don't actually need much magnesium in your diet, maybe certain dolomitic limestones would be just about right.
Reply With Quote
  #8  
Old 06-25-2012, 10:48 PM
njtt njtt is online now
Guest
 
Join Date: Jul 2004
Quote:
Originally Posted by Surreal View Post
Cite?
Don't be silly. Try using your brain. Most people do not take magnesium supplements. For most of the time mankind has been around, there was no such thing as a magnesium supplement, yet people do not commonly suffer from magnesium deficiency diseases. (If anyone did, you can be sure people would be trying to sell magnesium supplements to the gullible, regardless of any actual need.)

Most dietary supplements are unnecessary for most people who eat anything approaching a normal, reasonably balanced diet, although calcium is an exception in that some people, especially post menopausal women, do benefit from it.

Last edited by njtt; 06-25-2012 at 10:51 PM..
Reply With Quote
  #9  
Old 06-25-2012, 10:51 PM
Surreal Surreal is offline
Guest
 
Join Date: Mar 2002
Still waiting for that citation...
Reply With Quote
  #10  
Old 06-25-2012, 10:55 PM
njtt njtt is online now
Guest
 
Join Date: Jul 2004
Quote:
Originally Posted by Surreal View Post
Still waiting for that citation...
Try Google then.

Also, 2+2=4. Do you want a cite for that?

Last edited by njtt; 06-25-2012 at 10:57 PM..
Reply With Quote
  #11  
Old 06-25-2012, 10:59 PM
Surreal Surreal is offline
Guest
 
Join Date: Mar 2002
Quote:
Originally Posted by njtt View Post
For most of the time mankind has been around, there was no such thing as a magnesium supplement, yet people do not commonly suffer from magnesium deficiency diseases.
Has it ever occurred to you that people in our modern civilization might not be eating the same types of foods that humans were consuming throughout most of human history?
Reply With Quote
  #12  
Old 06-25-2012, 11:01 PM
Surreal Surreal is offline
Guest
 
Join Date: Mar 2002
Quote:
Originally Posted by njtt View Post
Try Google then.
I did, but for some reason I can't locate anything to support your claim that "most people will get all they need from regular food."
Reply With Quote
  #13  
Old 06-25-2012, 11:09 PM
al27052 al27052 is offline
BANNED
 
Join Date: Apr 2011
Posts: 1,331
Magnesium and calcium are antagonists. A number of degenerative diseases involve calcification, and magnesium is one of the best ways to reverse that, because it is, chemically, a perfect antagonist of calcium. Heart disease is, in my understanding, partially caused by the sharp calcium molecules scarring the artery walls. Then (because calcium tends to clump up and remain immobile, because of its chemical properties) calcium also becomes part of the arterial plaques.

Magnesium and calcium both have a calming effect (although magnesium's effect is stronger, IME), and I recommend supplementing both if your diet is deficient (and probably 99.9% of Americans are deficient in at least one of these).

IMHO, magnesium is the more important mineral, and the one less likely to cause serious health issues if over-consumed. Calcium is important to a point, but, beyond that, probably deleterious for most people, particularly those with a tendency toward heart disease.
Reply With Quote
  #14  
Old 06-26-2012, 12:02 AM
Surreal Surreal is offline
Guest
 
Join Date: Mar 2002
Quote:
Originally Posted by njtt View Post
Try Google then.

Also, 2+2=4. Do you want a cite for that?
No, but I would like a citation to support your claim that 68% < 50%:

http://www.ncbi.nlm.nih.gov/pubmed/15930481

Quote:
Abstract

OBJECTIVE:

Current dietary guidelines recommend adequate intake of magnesium (310-420 mg daily) in order to maintain health and lower the risk of cardiovascular disease. Recent evidence from animal and clinical studies suggests that magnesium may be associated with inflammatory processes. The objective of this study was to determine whether dietary magnesium consumption is associated with C-reactive protein (CRP), a marker of inflammation, in a nationally representative sample.

METHODS:

Analysis of adult (> or =17 years) participants in a cross-sectional nationally representative survey (National Health and Nutrition Examination Survey 1999-2000 [NHANES]) who were not taking magnesium or magnesium-containing supplements. The primary outcome measure was high sensitivity CRP (elevated > or =3.0 mg/L).

RESULTS:

Among US adults, 68% consumed less than the recommended daily allowance (RDA) of magnesium, and 19% consumed less than 50% of the RDA. After controlling for demographic and cardiovascular risk factors, adults who consumed <RDA of magnesium were 1.48-1.75 times more likely to have elevated CRP than adults who consumed > or =RDA (Odds Ratio [OR] for intake <50% RDA = 1.75, 95% Confidence Interval [CI] 1.08-2.87). Adults who were over age 40 with a BMI >25 and who consumed <50% RDA for magnesium were 2.24 times more likely to have elevated CRP (95% CI 1.13-4.46) than adults > or =RDA.

CONCLUSIONS:

Most Americans consume magnesium at levels below the RDA. Individuals with intakes below the RDA are more likely to have elevated CRP, which may contribute to cardiovascular disease risk.
Since you're such a fan of Google you might consider running a search on the "Dunning–Kruger effect."
Reply With Quote
  #15  
Old 06-27-2012, 12:34 AM
posskb posskb is offline
Guest
 
Join Date: Jun 2008
Thank you all for your answers. This was very informative. I will continue taking dolomite.
Reply With Quote
  #16  
Old 06-27-2012, 12:37 AM
posskb posskb is offline
Guest
 
Join Date: Jun 2008
I will add the pellets to my water and stir instead of swallowing them whole though!
Reply With Quote
  #17  
Old 06-27-2012, 01:09 AM
The Niply Elder The Niply Elder is offline
Guest
 
Join Date: Dec 2010
I thought i would add though, that consuming this rock stright up sounds like the most awful idea ever conceived (to say the least. No offense). Look. All these minerals have to be, what is called, "bioavailable", meaning that the chemistry in your gut has to incorporate it into your bloodstream. The only way to do this is though proper diet. Eat your vegetables, watch your intake of calories, eat a wide variety of foods, dont overdo any one food. Consuming massive incontrolled amounts of supplements has been shown to be carcinogenic.
Reply With Quote
  #18  
Old 06-27-2012, 10:29 AM
am77494 am77494 is offline
Guest
 
Join Date: Mar 2012
Dolomite MSDS shows that the only concern would be silica in the dolomite and it is minimal too.

Being a chemical engineer, I can say that the processes used for industrial chemical manufacture or ore/mineral processing are fairly simplistic and there are no quality checks like for food grade chemicals or pharmaceuticals.

So you may get one batch of ground dolomite which is perfectly okay for consumption - but another batch had some heavy metals drop into it from the grinding media degradation.

Since Calcium and Magnesium supplements are so cheap, why not just use that ?
Reply With Quote
  #19  
Old 06-27-2012, 03:08 PM
Michael63129 Michael63129 is offline
Guest
 
Join Date: Jan 2012
Quote:
Originally Posted by posskb View Post
Thank you all for your answers. This was very informative. I will continue taking dolomite.
Is there a reason why you don't want to get calcium and/or magnesium from food? Besides likely not being readily absorbed, calcium supplements (but NOT calcium from food) has been shown to contribute to atherosclerosis, perhaps because of the form it is in, or because your body needs other substances found in food to properly utilize it (as it does when absorbing it). As also mentioned, impurities might be a problem as well, depending on source and how much you eat.
Reply With Quote
  #20  
Old 06-27-2012, 09:43 PM
al27052 al27052 is offline
BANNED
 
Join Date: Apr 2011
Posts: 1,331
Quote:
Originally Posted by Michael63129 View Post
...calcium supplements (but NOT calcium from food) has been shown to contribute to atherosclerosis...
I'm unconvinced that a calcium-rich, magnesium-poor diet (completely without supplements) doesn't have a higher risk of atherosclerosis than the opposite.
Reply With Quote
Reply



Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 01:35 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.

Send questions for Cecil Adams to: cecil@chicagoreader.com

Send comments about this website to: webmaster@straightdope.com

Terms of Use / Privacy Policy

Advertise on the Straight Dope!
(Your direct line to thousands of the smartest, hippest people on the planet, plus a few total dipsticks.)

Publishers - interested in subscribing to the Straight Dope?
Write to: sdsubscriptions@chicagoreader.com.

Copyright © 2013 Sun-Times Media, LLC.