Magnesium

Question 1

Where is magnesium digested and absorbed

Answer 1

jejunum and ileum

Question 2

How is Mg absorbed

Answer 2

low conc: carrier mediated system
high conc: simple
30-60%

Question 3

What enhances bioavailability

Answer 3

vit D

Question 4

What inhibits bioavailability

Answer 4

phytates, fiber, unabs, fat

Question 5

How is Mg transported

Answer 5

1/2 free ionic state, 1/3 bound to albumin, rest part of various compunds

Question 6

How is Mg excreted

Answer 6

kidneys maintain homeostasis, unabsorbed Mg through fecal excretion, small amounts in sweat

Question 7

What are the metabolic roles of Mg

Answer 7

1) cofactor for enzymes (ATPases and phosphorylations)
2) primary divalent intracellular cation in tissues
3)extracellular needed for neuronmusclular function
4) Ca and K metabolism

Question 8

Is primary or secondary deficiency more common

Answer 8

secondary; seen in alcholics, severe diarrhea, excess Ca intake, renal disease

Question 9

DRI/RDA

Answer 9

310mg/day women
400mg/d male

Question 9

Signs of deficiency

Answer 9

nausea, vomiting, muscle issues, nervous system changes, low blood Ca

Question 10

UL

Answer 10

350mg from SUPPLEMENTAL Mg

Question 11

Toxicity

Answer 11

not likely; caused by impaired renal function

Question 12

Food sources of Mg

Answer 12

chlorophyll, green leafy vegetables, unrefined grains, nuts