Here's the post I wrote on Magnesium - took a few days to finish, but I began it before the Joy Diet post on creativity, so it shows up below the other!
Bottom line - most men & women in the US (& prob other 'developed' countries are low on Magnesium - women typically get half the daily requirement, & men a bit more! It's crucial for many functions (more than 325) & deficiency is linked to MANY disorders!
& supplements are pretty inexpensive, esp. considering how many benefits there are to receiving adequate amounts!