hi again, elaborating on the insulin aspect and tying back to the low magnesium levels seen during pregnancy (as touched on in one study cited above), here's a little more fleshing out of the scenario:
Magnesium deficiency produces insulin resistance and increased thromboxane synthesis.http://hyper.ahajournals.org/content/21 ... 1024.short
"...angiotensin II-induced plasma aldosterone concentration increased after magnesium deficiency. Analysis showed that all subjects studied had a decrease in insulin sensitivity after magnesium deficiency (3.69 +/- 0.6 to 2.75 +/- 0.5 min-1 per microunit per milliliter x 10(-4), p < 0.03). We conclude that dietary-induced magnesium deficiency 1) increases thromboxane urinary concentration and 2) enhances angiotensin-induced aldosterone synthesis. These effects are associated with a decrease in insulin action, suggesting that magnesium deficiency may be a common factor associated with insulin resistance and vascular disease."
details on magnesium-rich foods, target serum levels, etc may be found here: regimens-f22/topic2489.html#p15460
also in response to a separate question on a different thread, i just happened to write up a blurb on magnesium this evening: regimens-f22/topic2489-495.html#p205386
thought i'd hunt down something else on magnesium levels during pregnancy, just to be sure it's recommended
The effect of oral magnesium substitution on pregnancy-induced leg cramps.http://www.ncbi.nlm.nih.gov/pubmed/7631676
"OBJECTIVE: Our purpose was to determine whether women with pregnancy-related leg cramps would benefit from oral magnesium supplementation.
STUDY DESIGN: Seventy-three women with pregnancy-related leg cramps were interviewed about their symptoms in a prospective, double-blind, randomized trial. Initial serum magnesium levels and diurnal magnesium excretion was determined in 50% of the patients. Oral magnesium or placebo was given for 3 weeks, after which new interviews and laboratory analyses were performed.
RESULTS: Serum magnesium levels in these patients were at or below the lower reference limit, as is also often the case in healthy pregnant patients. Oral magnesium substitution decreased leg cramp distress (p < 0.05 compared with the placebo group, p < 0.001 compared with initial complaints), but did not significantly increase serum magnesium levels, excess magnesium being excreted as measured by an increase in urinary magnesium levels (p < 0.002).
CONCLUSION: Oral magnesium supplementation seems to be a valuable therapeutic tool in the treatment of pregnancy-related leg cramps."
the takeaway points being, the mag sulfate (an inorganic form) appears to have been very poorly absorbed, leaving these mothers deficient before and after the study, what little retention there was, was sufficient to alleviate some of the distress from leg cramps.
the other end of the spectrum:
Magnesium Intoxication in a Premature Infanthttp://pediatrics.aappublications.org/c ... /100.short
"This report of a premature infant with hypermagnesemia indicates that magnesium sulphate therapy for pre-eclampsia may have profound effects on the fetus. In this infant the toxic effects of motor and respiratory paralysis were immediately reversed when the serum magnesium level was lowered during an exchange transfusion.
in short, there can be too much of a good thing. reversible toxicity, fortunately."
based on this toxicity scenario, i had to find out more about how this mag sulfate therapy is delivered..:
Magnesium Sulfate in Eclampsia and Pre-Eclampsia: Pharmacokinetic Principleshttp://www.ingentaconnect.com/content/a ... awler=true
"It is usually given by either the intramuscular or intravenous routes. The intramuscular regimen is most commonly a 4g intravenous loading dose, immediately followed by 10g intramuscularly and then by 5g intramuscularly every 4 hours in alternating buttocks. The intravenous regimen is given as a 4g dose, followed by a maintenance infusion of 1 to 2 g/h by controlled infusion pump."
may i just say, wtf. this is status quo magnesium therapy for pregnant women?! educated dietary source magnesium with soluble, absorbable oral supplementation sounds a crapload safer than THAT