Go read the Disclaimer again. I am not a doctor. This is not medical advice. Seriously.
I avoided prenatal vitamins during my first pregnancy. During my second pregnancy, in part because I was still breastfeeding to a very limited degree, and partly because I was supplementing anyway due to some gum problems, I started taking a prenatal vitamin. I also started taking a magnesium-calcium supplement (2-1 ratio).
Partway through my second pregnancy, I heard a friend's second birth story, in which she was put in bed rest, ultimately hospitalized for HELLP or something along those lines and put on a magnesium sulfate drip. I don't recall if she ever seized or not, but in no way did it seem to me that she was overtreated.
Late in that pregnancy, I read some research indicating that magnesium sulfate drip for women likely to have premature labor improved CP outcomes in the resulting group of babies. This made a lot of sense to me (as an intervention, and how it turned out), which made me wonder if the increasing rates of HELLP might be attributable to increasing rates of magnesium deficiency in the general population. Since I'm in no position to do such a study, my interest lay in whether there might be a reason to expect us to be suffering from increased rates of magnesium deficiency. Indeed, there are several. Some medications interfere with magnesium. Supplementing calcium without supplementing magnesium can cause a deficiency. Soil depletion (from use of artificial fertilizer) might be a concern, as might diet.
A quick scan of on-line guidelines for choosing a prenatal vitamin suggests that the presence of magnesium is not a priority in these products (altho calcium, iron and folate are); it was no planning on my part that the vitamin I am taking includes magnesium. Altho the additional mineral supplementation was intentional, it was with a view to bone health, not pregnancy outcome. There are several reasons to add magnesium to a typical prenatal supplement. While iron and calcium are constipating, magnesium has a laxative effect; the result might be less difficult to live with. Restless leg syndrome and leg cramps are common complaints late in pregnancy, both of which are often (altho not always) alleviated by supplementing magnesium. Magnesium might help preserve one's bone health and who knows, might slightly reduce your chance of preterm labor.
As always, dietary change is better than taking a pill. Best of all, the usual suspects are high in magnesium, as well as iron and calcium: Dark Leafy Greens. But nuts, seeds, legumes, dairy products and many other foods also have substantial magnesium.
General Discussion of Supplementation.
Copyright 2008 by Rebecca Allen.
Created August 27, 2008 Updated August 27, 2008