Can magnesium supplementation help bring you calm? Should you take it for cramps or migraine prevention? If you do choose to take a supplement, how can you choose the right one?

Magnesium is an important mineral in our bodies and many of us either do not get enough of it or we may have habits that affect its absorption. Magnesium is hard to test for - commonly available and affordable tests just test the magnesium that is in our serum which will show up as low only if a deficiency is relatively severe. If our intracellular magnesium is low we cannot tell by a simple blood test (more expensive tests are available but not commonly used or covered by insurance).

The good news is that magnesium is readily available in dietary sources. Some foods that are rich in magnesium include nuts (1oz of almonds contains 20% of your RDA of magnesium) seeds, whole grains, beans, leafy vegetables, milk, yogurt, dark chocolate and fortified foods are great dietary sources. Simply looking for dietary sources of magnesium is best for most of us.

Things that will deplete your magnesium: certain medications including the blood pressure pill hydrochlorothiazide and proton pump inhibitors. Alcohol will also affect magnesium absorption as well as absorption of other important vitamins and minerals.

What if you rely on magnesium depleting meds and cannot get enough magnesium in your diet? Over the counter supplements abound for magnesium. While there are many forms of magnesium, the three forms that are most readily available, tolerable and inexpensive are magnesium oxide, magnesium glycinate and magnesium citrate. One is not better than the other in terms of efficacy and absorption BUT there are major differences in gastrointestinal side effects. Magnesium oxide is inexpensive and easily encapsulated, but it acts as a laxative at higher doses so you should avoid it if you are already prone to stomach upset or diarrhea. If you tend towards constipation magnesium oxide can be a good choice but you still want to start low and titrate up. A usual dosage is 250-500mg/d. Calcium glycinate is a great option for those who do not want the laxative effect or have sensitive stomachs. Magnesium citrate is a 3rd commonly found supplement which is easily absorbed but also tends to act as a laxative. While many over the counter magnesium supplements claim to treat anxiety or sleep better than another form of magnesium, we really do not have enough data to support using one supplement over another in terms of efficacy.

Are magnesium supplements useful as a treatment for anxiety or other health problems? There are lots of observational studies that show persons with anxiety tend to have low serum magnesium levels. Unfortunately we don’t have great data to go on regarding the effect of boosting those levels and its effect on anxiety.

What about other medical applications/benefits of magnesium? Magnesium has been shown to lower blood pressure. It is also helpful for some people as a means to reduce migraine frequency. There are also possible positive effects from magnesium on sleep, muscle cramping and blood sugar.

For migraine prevention in particular there is little to no risk in trying a magnesium supplement (mag oxide most commonly, but can try glycinate or citrate if oxide not tolerated or you are prone to loose stools). Here is a summary on magnesium prophylaxis in migraines

If you have a health condition that you think may improve with magnesium a good strategy is to take 250-500mg/d as tolerated and monitor your symptoms over a period of 3 months. If your anxiety is less, sleep is better, your blood pressure is better or your headaches are less frequent then continue supplementation.