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…

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.

It’s clay. Dirt.

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).

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…


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.

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.

Still waiting for that citation…

Try Google then.

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

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?

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.”

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.

No, but I would like a citation to support your claim that 68% < 50%:

Since you’re such a fan of Google you might consider running a search on the “Dunning–Kruger effect.”

Thank you all for your answers. This was very informative. I will continue taking dolomite.

I will add the pellets to my water and stir instead of swallowing them whole though!

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.

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 ?

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.

I’m unconvinced that a calcium-rich, magnesium-poor diet (completely without supplements) doesn’t have a higher risk of atherosclerosis than the opposite.