Magnesium testing and supplementation

Several studies have shown that most people these days are magnesium (Mg) deficient. However, diagnosing and treating those deficiencies is tricky.

The red blood cell (RBC )Mg test is probably the best "easy" test. Unfortunately, a normal result isn't enough to rule out a deficiency.

The Gold Standard in magnesium testing is the Magnesium Loading Test. The process involves having an IV containing a known amount of Mg, and
measuring 24-hr urine Mg before and after the IV. Using those numbers, you can calculate how much Mg the body held onto, and based on that amount, you can tell if you're deficient or not. Since an IV is costly and time consuming, most docs fall-back to the RBC Mg test if you're lucky, or the plasma test if not. The plasma test is one of the least reliable, most misleading tests around (plasma contains only about 0.3% of total body Mg).

[[MORE]]The reason the blood tests aren't very accurate is because blood is only store of Mg in the body -- it's also present in bones, muscle and other tissues.

After working through massive frustration with doctors on this issue over many years, my solution was self-experimentation. Here are a few things I've learned:

-- Mg oxide and Mg carbonate are pretty much useless when it comes to
correcting deficiencies
-- Time-release Mg chloride tablets work pretty well ("Slow Mag"), but take a long time
-- Liquid Mg chloride works faster than the tablets, but can cause GI upset and headaches because it gets into the body quickly (take with food and in divided doses)
-- The Mg chelates also work well, particularly Mg glycinate and Mg aspartate; orotate and taurate are also good
-- Mg citrate, although not as well absorbed as the chelates, also works well because it can be taken in a higher dose (1 tsp to 1 tbsp at a time), such as with "Natural Calm" (my current favorite form of supplementation)
-- Dark green veggies are a great source of Mg in food (chlorophyll uses Mg in a way that's analogous to how hemoglobin uses iron); chocolate is also a good source
-- Some medications and health conditions can cause the kidneys to leak Mg (where you excrete more than normal); hyperglycemia (high blood sugar) is one way that can happen
-- Something like 80% of the population is Mg deficient
-- Mg is used by over 300 enzymes in the body, and is required in order for muscles to relax
-- High calcium intake can interfere with Mg absorption
-- Common symptoms of Mg deficiency: high blood pressure, asthma, tension headaches, muscle cramps, constipation, anxiety, and depression