Now I'm feeling doubtful about the CALM. I called then two months ago myself and they told me it was corn and that they were hoping to find a new manufacturer and that they would then use the beet derived stuff. Hmmm!?
My same experience.... I called and asked about CALM too...was told it was corn derived. I also
emailed NAP and asked the source of their magnesium citrate (which if you take a lot of the formulas, it's almost in every single bottle). Never got a reply.
Just emailed them again. Will update if and when
I get an answer.