Ingested magnesium is not concentrated in the breast milk. Average natural concentration of magnesium in the milk is 31 mg / L (15 to 64 mg / L) which is barely affected by magnesium intake. Its low oral bioavailability makes the step to plasma infant from ingested breast milk is scarce, except in premature and immediate neonatal period that may be characterized by an increased intestinal absorption. Daily Magnesium needs for nursing mothers are estimated at 250 mg.Avoid chronic use or overuse.