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Magnesium Stearate in Multivitamins: Healthy?

Posted by Dona (Colville, WA) on 07/31/2006

Hi, I'm new to your web site and appreciate it a lot. Q: I've noticed that 99 percent of all vitamin supplements have added magnesium stearate and am wondering WHY and if this will cause an imbalance of magnesium? Thank you for your time. :) Dona

Replied by Ted Donate

Bangkok, Thailand
Dona: Magnesium stearate is a stearic acid with magnesium ions attached. It is used as fillers in vitamin capsules to prevent sticking during vitamin production. It also gives the vitamin tablets its waxy appearance and it melts at 88 degrees celsius.

As a result, any vitamin tablets with magnesium stearate will reduce bioavailability of the vitamins as it reduces the ability for vitamin to dissolve in your stomach. Just imagine eating a candle mixed with vitamins and you get the picture.

I will always try to avoid any vitamins with magnesium stearate, not only does it prevent the absorption of the vitamins by reducing the solubility, magnesium stearate alone cannot be used as a nutrition either. The only best thing I can say about magnesium stearate is to prevent or reduce constipation a little bit by providing some lubricating effect to your intestines, however this is so minor, it is not even worth using. When I take vitamins I go the old fashion way. I take them in either powder form or take vitamins in soft capsules. They get dissolve faster.

A test for bioavailability is to put your vitamin supplements in a glass of water. If the entire tablets will dissolve in less than 10-15 minutes then it is o.k. This is the approximate length of time an average vitamin spends its time in your stomach. So by the time it reaches the intestines, vitamin should be absorbed. Now for the bad news: no vitamins I have ever tested in tablet form passed the test. Capsules do, but not entirely.

The one form of vitamin that does pass the test is the most obvious ones, a vitamin in powder form and dissolve them yourself. This is what I do.

Parents have often come screaming at me all the time that they cannot raise their child's zinc or magnesium levels despite two years of supplementation.

The answer is simple, two fillings that seems to be interfering with absorption is the magnesium stearate, and also tricalcium phosphate. Therefore, it is best to avoid tablet form of vitamin altogether. The reason I know this fact is I used to moonlight making these vitamin tablets and just knew that companies don't care whether it is bioavailability, all the want is to get those numbers (mg. of minerals, or vitamins) show on the packaging since this is how consumers judge the quality of the vitamins.

The funny thing about bioavailable vitamins that manufacturers fear a lot is that people don't need to take them everyday. And as soon as they take it for the entire month, I found myself recommend them to pare of taking it and take only either once a week or two week and sometimes once a month. So in terms of sales, you can see why manufacturers rather give you an oxide form so that you can take them forever, without raising the mineral levels. It helps with sales, two years of sales is not bad, compared to a more bioavailable one which roughly calculates to only one month's sales for a better quality one. I make a very bad salesman, if you ask me. So that is why I avoid doing this kind of "vitamin business" altogether.

Here is the proper way (to be fair with everyone):

1. Vitamin and minerals should dissolve in 10-15 minutes in glass of water. Tricalcium phosphate often blocks absorption. Magnesium stearate will slow solubility and also block vitamin absorption.

2. Powder form is generally the best, followed by soft capsules, and tablets that dissolve in less than 15 minutes in the glass. Soft capsules usually will be better than tablets because to get tablets in their "form" the machine must be pressed heavily, making them quite invulnerable often even to moisture.

3. Absolutely avoid all ingredients in oxide form. Oxide forms of mineral include magnesium oxide, zinc oxide, etc. They don't dissolve in water and will generally stay in their original form. It is poorly absorbed. The second worse form is carbonate form of mineral, such as magnesium carbonate, zinc carbonate, etc. These are also poorly soluble. Aspartate are soluble, but they are toxic of the likes similar in some ways to aspartame, such as magnesium aspartate. Generally the best form are also the hardest ones you can find, minerals in the form of citrate, bicarbonates, and chloride. These has been my favorites.

Therefore, it is best to generally avoid magnesium stearate that is used in fillings. If you INSIST in using it, then may I suggest you get the tablet and pound them in mortal and pestle so they become powder. Take this ALONG with the food you eat or mix it with the food. This is the best way to work around a problem, make them into powder form again. I know the kids won't like the powder, so you just hide them in honey, molasses, or strong food with strong taste. You just have to get your vitamin to go stealth. Ted

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