• Key idea: ON THE BOARDS, ALCOHOLISM = MALNUTRITION!
• Hypomagnesemia –> Refractory hypokalemia and hypocalcemia
• Key idea: In the setting of hypocalcemia, important to always check a magnesium level and a serum albumin level (low albumin –> low total calcium)

https://step-prep.org/tutoring/

Everything you need to know about Ca, Mg, K And Alcoholics

Dec serum Ca2+ >> Inc PTH secretion

Inc serum PO4− >> Inc PTH secretion

Dec serum Mg2+ >> Inc PTH secretion

Vert low serum Mg2+ >> Dec PTH secretion

3rd point from step 1 knowledge made me choose inc PTH but it shouldn't. This guy has mg of 0.4 which is very low and remember dr ryan “some Mg is needed to release PTH hormone”.

In alcoholics,

Low Mg (Decreased intake) >> PTH resistance + Inhibit PTH release >> Low Ca, Normal to Low Phosphate (can be normal due to low PTH, tends to be low due to nutrition and urinary loss in alcoholics).

Hypomagnesemia is Common in alcoholics due to ↑ urinary loss, malnutrition, acute pancreatitis and diarrhea. Does not respond to calcium. Magnesium Repletion quick PTH recovery, calcium takes time to reach normal level.

Alcoholics also have low K+ refractory to supplementation. This is also due to low Mg. Basically Mg prevents urinary loss via ROMK channel. Mg supplementation is needed to reach normal K level.

Bottom line, Alcoholics are very likely to have low K, Ca, Mg. This can accompany low to normal PO4. This is independent to whether or not CLD is present.

Hypoalbuminemia results in apparent hypocalcemia. Free calcium is unchanged and the patients don't have sx of hypocalcemia, but total calcium stores are depleted (which is what the lab measures).

Deficiency of calcium, magnesium, or phosphorus may be related to decreased intake, malabsorption, or renal losses. Calcium deficiency may also be secondary to magnesium or vitamin D deficiency. This patient's magnesium was low. Calcium, magnesium, and phosphorus levels should be checked in all patients with an alcohol use disorder or heavy alcohol use.