Page 8 of 16

Re: all things magnesium

Posted: Thu May 01, 2014 9:24 am
by THX1138
I just got my magnesium RBC test results:

Magnesium, RBC-------------- 3.5 - 7.1 mg/dL --------- 4.6

and from about a week earlier:

Serum Mg--------------------- 1.2 - 2.1 mg/dL --------- 2.0

Re: all things magnesium

Posted: Thu May 01, 2014 1:39 pm
by jimmylegs
nice! so recall:

thx: ... ml#p223983
you want to be an optimum of 6.0-6.5mg/dL in a range of 4.2-6.8mg/dL
me: ... ml#p223987
ok so 6.0-6.5 for rbc mag probably lines up quite nicely with 2.3-2.7 serum mag. good good good!
Therefor my Mg-RBC came back with (correct) low: 3.8mg/dl (good would be ~6mg/dl, optimal/heaven would be 7mg/dl).
On the other hand the serum Magnesium was optimal with 1.97mg/dl (range 1.7 to 2.2 mg/dL) .

RBC mag...: 3.8........4.6......6.0-6.5
S mag......: 1.97.......2.0......2.3-2.7

makes sense to me! looks like RBC and serum mag move together and can both show as low when appropriate target ranges are used.

does anyone else have simultaneous or near-simultaneous RBC and serum mag tests?

Re: all things magnesium

Posted: Thu May 01, 2014 5:58 pm
by muse
Just for the records.

My serum Mg was tested with 1.97mg/dl and the reference of MY pathology lab was 1.70-2.90mg/dl.
All good the lab said and so did the GP.

My Mg-RBC was tested with 3.8mg/dl and it should be 6.0mg/dl.
The lab said to low and the GP: "I have no f* clue".

I'm 100% with Carolyn Dean, Mark Sircus, Morley Robbins/Rick Malter etc.. Testing serum Mg is worthless. You have to look for the Mg body tissue values and not for the 1% Mg in your blood stream because the body will do EVERYTHING to keep the Mg-level in the blood serum constant to keep the system running and to prevent worse case scenarios like heart attacks etc..

Re: all things magnesium

Posted: Thu May 01, 2014 7:51 pm
by jimmylegs
the reference of MY pathology lab was 1.70-2.90mg/dl.
this is exactly the point (we've already been over lab to lab range variation above; we can add yours) - the ranges are certainly not useful.. but serum level info absolutely is.

yes, a large percent of tissue magnesium is readily exchangeable into serum. yes, the body works hard to keep serum levels constant. and yet still, in study after study, healthy mean SERUM levels are measurably distinct from patient serum means (and the range i've been able to specify is based on published recommendations as well as patient means in research - so there are no doubt numbers like 2.90 mg/dL captured in the raw data).

perhaps this distinction results in some part from low RBC magnesium being available for transfer, or potentially a cofactor deficit affecting magnesium release from tissue into serum.

if the body was that successful at maintaining a specific serum magnesium level, we wouldn't see the variation that we do see, repeatedly, in research (and which has been quite clearly and positively correlated with cardiac illness, since you mention it)

Low serum magnesium concentrations predict cardiovascular and all-cause mortality ... 5011004734

Re: all things magnesium

Posted: Thu May 01, 2014 8:28 pm
by muse
Just let us agree to disagree, jimmylegs. For me, C. Dean, M. Sircus. R. Malter, M. Robbins etc. the serum Mag-level is worthless for you it's not. I'm fine with that. :smile:

Re: all things magnesium

Posted: Thu May 01, 2014 11:50 pm
by jimmylegs
they'll come around at some point, i'm ok with it not being right this second :)

Re: all things magnesium

Posted: Sat May 03, 2014 12:14 pm
by THX1138
I think it would be helpful for all of us if some more of us would post back-to-back serum Mg vs RBC Mg results. So far we have THX1138 and muse with very closely spaced results from both tests. I will definitely request both the RBC and Serum Mg tests the next time I get my Mg tested. I will ask the lab to use the same blood for both tests.

It is interesting to me that my serum Mg level (2.0mg/dL) was very near the top of the "normal" range at my local lab (1.2 - 2.1 mg/dL). but my RBC mag came back at 4.6 mg/dL - nowhere near the top of the "normal" range of 3.5 - 7.1 mg/dL.

I'm certainly going with the idea that I need more Mg because:
1) I have several Mg deficiency symptoms that could be taken for MS symptoms. However, they respond favorably to proper Mg supplementation.
2) Most people do Not get enough Mg, including myself for most of my life.
3) A doctor told me that people with MS excrete Mg at an unhealthy rate (Mg wasting).
4) My serum Mg is not in a healthy range, nor is my RBC Mg.

Re: all things magnesium

Posted: Sun May 04, 2014 4:44 am
by jimmylegs
noting of course, THX, that we have established thoroughly that normal ranges are off for serum mag, and that what we're really after is 2.3 - 2.7 to match healthy controls' average serum mag

Re: all things magnesium

Posted: Sun May 04, 2014 10:51 am
by CarolynDean
I was invited to give an opinion on blood testing for magnesium.

I outline the problem with serum magnesium blood tests in this article about Kidney Disease and Magnesium. ... ition.html#

In my book The Magnesium Miracle I talk about serum magnesium being in a very tight range to keep the heart perfused with magnesium. If the serum levels get low, the body automatically pulls magnesium from storage in muscles and bones. So, it will always look "normal" until there is dangerous depletion. BUT, the range of magnesium levels is taken from the sick population who are 80% deficient in magnesium.

I highly recommend the Magnesium RBC blood test, which has a wider range: 4.2-6.8mg/dL but I advise an optimum of 6.0-6.5 mg/dL. If you are 4.2, you are dangerously low in magnesium. This blood test can be obtained from an online lab for $49.00.

Here are two of my articles with some information about magnesium and MS. ... and-teeth/

Magnesium deficiency is intimately involved with every disease that affects the muscles and nerves.
Magnesium is no longer sufficient in our diet, thus supplementation is advised and is very safe.

Carolyn Dean:

Re: all things magnesium

Posted: Sun May 04, 2014 5:01 pm
by jimmylegs
thanks for your note dr dean :)
So, it will always look "normal" until there is dangerous depletion. BUT, the range of magnesium levels is taken from the sick population who are 80% deficient in magnesium.
very true.

on a related note, as you can see above, we've spent a lot of time critiquing 'normal' ranges for serum mag, and identifying mean serum levels seen in controls, as distinct from those seen in a wide variety of patient groups. we've seen the warning for 'normal' serum mag issued by ismail et al (2010), as well as proposed revisions to lower cutoffs for serum mag ranging from 2.2 to 2.3 mg/dL.

we've also noted that when these numbers are used as lower cutoffs for serum mag, that levels which would typically pass muster as 'low normal', are instead recognized as just plain low, and do correlate with low RBC mag. i went back into the older literature recently, that criticized serum mag as a poor indicator of tissue mag. it's quite clear that it's only the range definitions that create the problem of comparing serum and RBC mag.

this figure shows the positive relationship between serum mag and RBC mag during depletion and repletion: ... nsion.html
(i note that serum mag was suboptimal throughout)

still digging for more research comparing serum mg and rbc mg.

every TiMS member for whom i have serum results, has tested 'normal' - but below the 2.2 to 2.3 lower cutoff proposed for optimal health. this is why when it comes up, i suggest that patients ask for and personally evaluate their own copy of their results, and not accept any assurances that levels are 'normal'.

members have achieved improvements through working to push serum levels into the 2.3-2.7 mg/dL range. we're aware that such levels would be characterized either as high normal, or outright 'high' serum mag, depending on the local lab's range settings.

beyond the debate re serum vs RBC mag, we've also spent a significant amount of time on refractory mag issues and cofactors. it's all very interesting!

you might also enjoy our ongoing debate re mag (as well as other cofactors) as a critical consideration for those taking vit d3 supplements: ... 5-765.html

Re: all things magnesium

Posted: Fri May 09, 2014 11:38 am
by Lynn62

I had my magnesium level checked back in 2012 and it was "normal" at 2.0 mg/dL with a reference range of 1.8-2.5.

Is this really a good level and is it a serum level or a rbc level?

I have an appointment next Friday with my neuro and plan to ask about magnesium supplements among other things.

What dose of magnesium glycinate do you recommend?


Re: all things magnesium

Posted: Fri May 09, 2014 2:24 pm
by jimmylegs
hi lynn,

given the level and the range at your local lab, 2.0 mg/dL appears to be a serum mag result and qualifies as low normal, a part of the range known to be associated with deficiency states.

some authors have proposed lower cutoffs from 2.2 to 2.3 mg/dL. the upper end of the normal range at my local lab, which i have seen published as a healthy controls *average* in research, is 2.7 mg/dL.

so, i would aim for a serum level of 2.3-2.7 mg/dL, and I would try really hard to get as much of that as possible from dietary sources.

i would recommend supplemental dosing of magnesium to suit your current serum mag status, plus your level of dietary intake, as well as your habitual intake of other factors that might have a positive or negative influence on absorption.

if your serum levels are below 2.3, i'd suggest a daily total intake of 600mg per day. once your levels are at least 2.3, you can aim for daily intakes from 300-400mg daily.

*if* we can assume your levels are currently about the same as in 2012. a good place to start could be to calculate your current dietary intake of mag, to see how close you are to 600mg. then you can work to boost dietary intake. and after that, you could supplement with mag glycinate to make up the balance.

list of healthy mag sources with serving sizes and mgs per serving: ... #foodchart

it's best to do as much as possible from a varied selection of magnesium rich foods, since these will have a better mix of co-factors as compared to isolated supplement products.

overall, to ensure absorption you could work to ensure as little interference as possible from:
- depleters such as physical stress, diuretics (eg caffeinated beverages, alcohol), and/or medications (such as proton pump inhibitors (PPIs));
- binders (such as gluten, phosphates);
- excessive intake of competitors (such as calcium above 1200mg per day.. twice daily mag (the commonly seen 2:1 ratio ) is a maximum, not a target).

hope that helps, sorry i can't give you a blanket recommendation other than the daily overall targets depending on whether you're looking to increase or maintain.. and even then, other than how you feel, you still need a bit of follow up testing to establish efficacy.. not the simplest thing in the world!

Re: all things magnesium

Posted: Sat May 10, 2014 10:02 am
by Lynn62
Thanks Jimmylegs! I bookmarked the list of magnesium rich foods. I do eat some of them already, but probably not enough. I take 2000iu vitamin d3 at breakfast because I am low in that. When I start supplementing magnesium, do I take it with the vitamin D? I vaguely remember reading one of your posts about vitamin d and magnesium interacting. I also take a multivitamin, 1 teaspoon of Metamucil clear and natural, and 1 low dose aspirin with the vitamin d at breakfast. At dinner I take a probiotic 14 billion. At bedtime I take LDN 3mg.

Re: all things magnesium

Posted: Sat May 10, 2014 11:50 am
by jimmylegs
hi again :) given the vit d3 intake, i'd suggest taking half of any supplemental mag glycinate at the same time as the morning d3, and the other half at some point later in the day (magnesium has plenty to do in the body besides interact with d3, and also can be a nice way to help wind down for sleep).

personally, at this point, if i am going to take mag in the evening it is more likely to be mag citrate than mag glycinate (i keep both kinds handy), and it is ideally taken well before lying down for sleep, and/or prior to supper or some sort of evening snack. the related cautionary tale is here: ... ml#p153097

which multivit product are you using, by the way?

Re: all things magnesium

Posted: Sat May 10, 2014 4:12 pm
by CarolynDean
I have real concerns about high dose Vit D supplementation (over 1,000iu per day) because it Vit D draws on magnesium for its transformation into the active form. So, people who are already low on magnesium start manifesting mag deficiency symptoms. I have blogged about that and written about it in my Magnesium Miracle 2014 edition. Google Vit D, magnesium and Dr. Carolyn Dean for more details.