How does abnormal serum magnesium cause hypocalcemia?
• Magnesium levels below 1 mg/dL produce PTH resistance. With more severe hypomagnesemia, the secretion of PTH can also be impaired. Correction of the hypocalcemia requires first restoring magnesium.
• Magnesium levels over 6 mg/dL can suppress PTH secretion causing hypocalcemia.
