Serum magnesium

mmol/L · Vitamins & minerals

Serum magnesium reflects extracellular magnesium — useful for severe deficiency but an imperfect marker of total body status.

Pregnancy increases renal clearance and fetal demand. Very low values warrant clinical review; borderline results may still matter when cramps, hypertension, or poor dietary intake coexist.

How to read it

Trends and symptoms matter. Dietary magnesium from nuts, legumes, and whole grains supports status; supplements only after discussing dose with your clinician.

Trimester context

Stage	For the mother	For the baby
First trimester	—	—
Second trimester	Demand rises with placental and fetal growth.	Magnesium supports bone and neuromuscular development.
Third trimester	Adequate status may support blood-pressure resilience and sleep quality.	Late fetal accretion continues until term.