Is it safe to take 600mg of magnesium while pregnant? Have bad constipation and this always helped before. Nothing else is helping.

CONSTIPATION. If you are pregnant specially 1st trimester, always ask your OB what rx you take because it might affect the baby. Magnesium so4 can be taken as much as 15 to 30 gm/ day, milk of magnesia (magnesium hydroxide) 30 to 60 cc/day.