What type of magnesium supplements to take? - High & Low Blood Pressure Message Board

trajan · 07-03-2006, 10:51 AM

I have read here on the board and other articles that taking a magnesium supplement may help reduce BP. But I cannot figure out what type to take as there are many different types of magnesium supplements!

Would anyone have any recommendations? Thanks

rigel434 · 07-03-2006, 11:14 AM

I'm an expert of sorts on this as I got hypomagnesemia from taking diuretics. It can take a long time (many months) to replenish your body supplies so you need to do it correctly.

The one thing NOT to take is the magnesium oxide which is cheapest and is what you usually see in stores. Studies show only 4% of that is absorbed in the body. I personally take magnesium taurate - do a web search on that. Magnesium citrate is absorbed well but tends to produce loose stools quicker.

But remember you need to balance magnesium with potassium and especially calcium. Every person has a correct balance for them- for me it seems to be 1:1 calcium to magnesium.

Lenin · 07-04-2006, 05:42 AM

I will take a different approach and recommend magnesium oxide highly.
Since magnesium is very soluble there is no need to take an expensive chelated version except to enrich the supplement industry. It's easy solubility in stomach acid is one of the reasons that it (as milk of magnesia) has been used for millennia to neutralize stomach acid.

Kidney stones are composed of either calcium oxalate (the most common) or urate stones (uric acid, ammonium urate etc.) The latter occurs in people with gout.
If anything, excess magnesium will help a bit to prevent the formation of calcium stones, not cause them.

Something like 250 or 500 mg. magnesium supplementation is a good idea, especially if your diet is short of it or you are taking a diuretic.

If for some reason other than price you prefer the citrate or another complex, it will work perfectly fine as long as you take enough. The larger the complexing molecule the less magnesium per unit weight and some of these complexes are big, big molecules and may contain only 5-10% magnesium. So buy for MAGNESIUM weight not something like "200 mg. Magnesium Citrate" which contains little more than an insignificant 20 mg. magnesium.

rigel434 · 07-04-2006, 05:34 PM

Could be, but here's what one study showed:

Magnesium bioavailability from magnesium citrate and magnesium oxide
J. S. Lindberg, M. M. Z*****, J. R. Poindexter and C. Y. Pak
Center for Mineral Metabolism and Clinical Research, University of Texas, Southwestern Medical Center, Dallas 75235.

This study compared magnesium oxide and magnesium citrate with respect to in vitro solubility and in vivo gastrointestinal absorbability. The solubility of 25 mmol magnesium citrate and magnesium oxide was examined in vitro in solutions containing varying amounts of hydrochloric acid (0-24.2 mEq) in 300 ml distilled water intended to mimic achlorhydric to peak acid secretory states. Magnesium oxide was virtually insoluble in water and only 43% soluble in simulated peak acid secretion (24.2 mEq hydrochloric acid/300 ml). Magnesium citrate had high solubility even in water (55%) and was substantially more soluble than magnesium oxide in all states of acid secretion. Reprecipitation of magnesium citrate and magnesium oxide did not occur when the filtrates from the solubility studies were titrated to pH 6 and 7 to stimulate pancreatic bicarbonate secretion. Approximately 65% of magnesium citrate was complexed as soluble magnesium citrate, whereas magnesium complexation was not present in the magnesium oxide system. Magnesium absorption from the two magnesium salts was measured in vivo in normal volunteers by assessing the rise in urinary magnesium following oral magnesium load. The increment in urinary magnesium following magnesium citrate load (25 mmol) was significantly higher than that obtained from magnesium oxide load (during 4 hours post-load, 0.22 vs 0.006 mg/mg creatinine, p less than 0.05; during second 2 hours post-load, 0.035 vs 0.008 mg/mg creatinine, p less than 0.05). Thus, magnesium citrate was more soluble and bioavailable than magnesium oxide.

Lenin · 07-05-2006, 06:30 AM

rigel,

You may be right but I'll withhold judgement til I see another study. I have never held as bible what I read in the JACN and this 16 year old study is all I can find.
If they were trying to determine the amount absorbed, isn't it perhaps a bit wrongheaded to measure the amount EXCRETED? Like looking for an agent to boost calcium absorption into bone by trying to find the agent that causes the most calcium LOSS?

But, like I said, you may be right about the citrate formulation...or else citrate MAY be just acting as a diuretic?