Magnesium

what is the normal range for magnesium?

1.3–2.3 mEq/L

major body location of magnesium

intracellular fluid; second most abundant ICF cation after potassium

key roles of magnesium

supports nerve and muscle function; permits muscle relaxation; promotes vasodilation to help regulate BP

what hormone regulates magnesium balance?

parathyroid hormone (PTH)

where is magnesium absorbed?

small intestine (gut)

relationship: magnesium and potassium

interact and can compete; low magnesium makes potassium imbalances harder to correct

relationship: magnesium and calcium

often low together; both influenced by PTH

pattern to remember for magnesium levels

low magnesium = excited and hyperactive; high magnesium = calm and quiet

main systems affected by magnesium shifts

neuromuscular; cardiovascular (rhythm and BP); CNS

main effect of magnesium on muscles and nerves

calms muscles and nerves

why can low magnesium cause cramps and tremor?

loss of magnesium’s relaxation effect makes neuromuscular activity hyperactive

why can high magnesium lower reflexes and slow breathing?

excess magnesium depresses neuromuscular transmission and smooth/skeletal muscle activity