I always have magnesium tablets in my cupboard. Once I did not quite feel like my usual self, a good friend and pharmacist suggested taking magnesium. 'It calms your nervous system, and aids good sleep' she said. It also gets rid of nasty leg cramps and I did take quite a high dose during pregnancy to keep braxton hicks under control. Careful though, taking too much can be an alternative to laxatives. If you do not want to take tablets you can also go for magnesium rich food - like leafy greens, nuts and seeds and even dark chocolate.