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!
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.
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.
Magnesium bioavailability from magnesium citrate and magnesium oxide
J. S. Lindberg, M. M. Zobitz, 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.
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?
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?
I had a BIG problem with this phrase:
Quote:
Magnesium oxide was virtually insoluble in water and only 43% soluble in simulated peak acid secretion (24.2 mEq hydrochloric acid/300 ml).
A chemist wouuld NEVER make such a statement because it depends on the amount of solution. Thus an amount of a base to react with an acid that dissolves to the tune of 43% will dissolve to the tune of 86% if the acid amount is doubled. See what I mean. For example, little MgO might dissolve in a tbsp. of HCl but a LOT more would dissolve in a quart. There's no such thing as "43% soluble."
But, like I said, you may be right about the citrate formulation being more soluble ...or else citrate MAY be just acting as a diuretic?
Thanks all for the input. Here is my situation. Around 5 years ago I was 30 lbs. overweight and went for a physical to find that my bp was 140/90 and at times higher. My doctor put me on a bp med and I swore I would be off it in a month. Within a month I lost the 30 lbs. and was able to get off the meds. Over the past 5 years my bp has been fine, there have been days that it would be a little high but I supplement it with Hawthorne which seems to help. I also run 5 miles a day 5-6 days a week. Over the past year I have not been monitoring it everyday as I used to and it has creeped up on me...I have readings of 131/86, 117/79 and yesterday I was 138/89 for a while. Mainly during the week when I am exercising I will be between 117/79 - 130/85. I cannot seem to keep my bp consistent. I had a cardiolite stress test a few months ago and everything was fine. I have seen the cardioligist about the bp issue and he says that its up to me whether to go on meds as I am borderline. I don't want meds, I am 40 yrs old and don't want to get started with that. I eat a low sodium diet and meat only once a week, the rest of the time is fish, tofu and seitan. I also take vitamin supplements. As far as lifestyle change there really is not much I can change. My body fat is currently 23-25% which is a little high and I need to lose 10 pounds. Currently I am 168. Is there anything else that I can do to reduce the bp? Thanks again for the great advice.
Honestly, magnesium oxide should work fine for someone thinking preventitively and for general health.
I am trying to correct hypomagnesemia, which can take many months if not longer, so I need the Rolls Royce of magnesium supplements. I thought I had it licked a while back but then I twisted my knee and didn't exercise for a month. My muscles atrophied and I know now that magnesium FLIES out of the body with muscle atrophy. Astronauts lose a dramatic amount of body magnesium on a 10 day space flight and 60 percent of bedridden ICU patients are hypomagnesemic. So now I've got the twitches again, especially in the calf of the leg I couldn't use. It's more annoying that anything but it's a frequent reminder that my electrolytes are off. At least my heart appears to have retained the magnesium because I haven't had another episode of tachacardia.
Incidentally, do a web search of chlorthalidone and magnesium and you'll find a study saying that chlorthalidone shouldn't be used because of the dramatic depletion of magnesium it causes. I don't think the ALLHAT study, which used chlorthalidone as the diuretic, tested for magnesium. The ACE inhibitor I'm taking apparently encourages magnesium and potassium retention because it inhibits production of aldosterone, which causes the kidneys to secrete both of them.
Incidentally, magnesium is a fascinating mineral- it's the most important of the electrolytes because it controls the entry and exit of potassium and calcium in the cells. That's why people who have both low magnesium and low potassium and/or calcium in their cells only get better after their magnesium improves. I saw one study of a guy with hypokalemia (low potassium) who was given intravenous potassium chloride and it strangely didn't improve his intracellular potassium. So they suspected hypomagnesemia, gave him a magnesium sulfate IV, and his intracellular potassium normalized!
I don't think you have any need to worry about your BP. It's never constant and your is always below 140/90, usually FAR below it. Don't even think about medicating it.
Rigel,
I agree about chlorthaldone. I am very accuatomed to years and years of daily HCTZ but I took ONE of my mothers chlorthalidones many years ago to compare it to HCTZ. I started peeing and peeing and I thought I'd never stop. I got weak and trembly and I began to fear a seizure. It was truly frightening and I'd never try the stuff again. To think that ONE PILL could so blow my electrolytes out of the water and perhaps even induce severe dehydration seems almost beyond belief.
When I read ALLHAT, I got the shivers!
I don't know HOW anyone could take it on a daily basis.
