I am not taking a mag supplement but I do take epsom salt baths 2-3x a week. I am pregnant (28wks) and I think because the baby is starting to grow bones faster right now that I REALLY need the mag/cal. I find if I do not take the baths I get charlie horses/leg cramps all night, then I take an epsom salt bath the next night and I am fine. I do believe the mag is helping but couldn't tell you what dosage it would be. I am debating starting the peter gilliham natural calm.