Drink soylent, never get enough magnesium


This might have been addressed elsewhere, but the fact that magnesium oxide is being used is either a gross oversight or proof that the soylent company has no clue about nutrition. magnesium oxide is only 4% bioavailable, compared to the citrate which is 30%.

ideally the Chelate would be used, (for all minerals, Ca, Mn, Mg)
the chelate is still only 30% bioavailable, but you can get around this because the magnesium is bound to an amino acid. there is a limit to the amount of magnesium you can absorb in you stomach at a given time, but not protein. So more total magnesium can hit your system at once.


Yes, several community members have advocated for the replacement of calcium carbonate and magnesium oxide with calcium citrate and magnesium citrate. See the below post (and thread) for more details.

We are hoping that Rosa Labs looks into this for Soylent 1.4.


Yeah, this has been talked about - and I’m surprised it wasn’t adressed in the latest Soylent formula change.

Best thread on this, specifically & IMO:

(it’s also suspected to be a major cause of the gas problem)


Im surprised they havn’t changed these two ingredients yet either… But I hope that it is in the pipeline as next change :slight_smile:


We need to bear in mind that there’s a difference between taking magnesium as a supplement versus magensium with food - magnesium oxide’s bioavailability is dependent on exposure to strong stomach acids.

If you take oral magnesium oxide in the absence of a meal, your stomach produces little acid and the magnesium passes through the stomach quickly.

If you take magnesium oxide with a meal, the stomach secretes a lot of acids and the meal takes longer to exit the stomach.

Research shows that bioavailability of magnesium from, say, mineral water, goes up with even a light meal.

In context of a magnesium supplement for a food product, magnesium oxide is not nearly as bad as the naysayers say.


You are forgetting that stomach acid is neutralized by soylent because it contains an antacid: Calcium Carbonate.


Bear in mind that calcium carbonate is taken in large doses to act as an antacid - thousands of milligrams. Soylent contains maybe 800 mg (exact formula unavailable), and that’s split into three or four meals, so no more than 266 mg or 200 mg per meal.

Tums Utlra 1000 tablets contains 1000 mg calcium carbonate each. Dosage instructions: take two to three tablets as symptoms occur.

Tums Regular contain 500 mg each, with instructions to take two to four tablets as symptoms occur.

So as an over-the-counter antacid, you take 1000 to 3000 mg of calcium carbonate per dose. Soylent contains 266 mg or less per meal.

Your stomach acid is not “neutralized” by Soylent. Your stomach produces additional acid as necessary for digestion, maintaining acidity at a pH of around 4 or 5. The pH in your stomach is more acid when empty, around 2.0, but ranging 1.5 to 3.0; when you eat a meal, the acid works on the food, but the food raises the pH of the stomach. The body secretes more acid as necessary to keep the pH around 4 or 5 until the food has passed; when the food is gone and the pH has dropped to the 2.0 range again, secretion reduces or stops.

The amounts of alkaline substances in Soylent and other normal foods - including, but not limited to the calcium carbonate - should not overwhelm the normal function of the acid system in the stomach for healthy people.

Incidentally, after the food passes the stomach and goes to the intestine, your body produces bicarbonate itself, in order to neutralize the remaining acid - it produces as much as necessary to get the pH up to about 8 (on the basic side; 7 is neutral); the pH in your small intestines is maintained at around 8.0.


Lower bio-availability doesn’t mean that your not getting enough. It just means that you need more of that form of magnesium in order to get the proper amount. As long as Soylent has the right amount of the oxide to provide you with your daily requirements after absorption then you’re getting enough.


I wonder whats the bio-availability of magnesium oxide with food.


A single study has shown 4% bioavailability of magnesium oxide


First, the primary source of Magnesium in Soylent is not Magnesium Oxide, but oats and rice. Oats are 0.144% Mg by mass. 110g of oat flour brings 158.4mg. Rice protein also has Mg at 0.159%. 102g of that provides another 162.18mg, already putting us above the “Requirements” level of the IOM. To reach the recommended levels, we need another 100mg. Just to be safe, we include ~250mg of magnesium oxide. Alternative sources such as citrate is known to cause digestive issues at these levels. Chelate would be preferred but it is very expensive. Magnesium Chloride is too salty.

Second, I take issue with the experimental method above. The body seeks homeostasis. Yes the IOM suggests 400mg / day of Mg, but this does not necessarily mean that your body will “consume” 400mg of Mg the same way it would metabolize starches and lipids. Elemental Mg stays intact of course, and is eventually excreted in urine. Instead, this amount roughly ensures ionic balance in the blood where and when needed. Unless the subjects in the study were suffering from magnesium deficiency, I would not expect them to absorb anywhere close to 100%.

A better study, such as this one (http://www.ncbi.nlm.nih.gov/pubmed/16548135) showed that actual Mg absorption when needed varied from 50%-67% among different salts, including magnesium oxide, though magnesium gluconate is slightly better. Our testing has not shown any signs of magnesium deficiency. If we begin to see any evidence we will promptly switch to the slightly more expensive magnesium gluconate. Note that with the lower bound of 50% absorption our Magnesium Oxide overage still places us comfortably above the IOM recommendations.

edit: Fixed link thank you @MentalNomad, and good point that bioavailability in water alone is generally lower. When taken with “food”, as is presumed to be the case with Soylent, uptake is higher. Either way I think this is worth testing further.

Polyphenols? Magnesium oxide? Vitamin D2?
Suggestions on v1.3 in here please
The Real Problems With Soylent Are Not Fixed In Version 1.1

Ah, there we go. :smile:


Both of your links point to Coudray, et al - you might want to edit/adjust.

Coudray, et al is a good study because it used magnesium within foods and showed that absorption is adequate in all cases, given that the rats were depleted of magnesium to start with. That is, if you need magnesium, the body gets it from pretty much any form, when given with food.

The 4% bioavailability figure is not based on a single study, as I recall - but it is, in fact, based on bioavailability when administered in water. In that condition, many vitamins/minerals have reduced uptake; that’s why vitamins/minerals are recommended to be take with meals.


I started getting involuntary eye movements when I went 100% Soylent and also had difficulty getting to sleep. The doctor advised me to take magnesium chelate which seemed to fix the problem.

The doctor did seem to think some people needed more magnesium than others - so perhaps I need more than the average person.


Does it seem like these changes have made it into 1.4?