Magnesium and Sulfur (The Final Macrominerals)

Question 1

Is magnesium found extracellularly or intracellularly?

Answer 1

Both

Question 2

Total body magnesium

Answer 2

20g

Question 3

Locations of magnesium

Answer 3

75% complexes with calcium in bones
Also found in blood

Question 4

Forms in which blood magnesium is found

Answer 4

60% ionized
30% bound with proteins
10% complexes with other ions

Question 5

Sources of magnesium

Answer 5

Cereals, nuts, beans, vegetables, milk and meat

Question 6

Biochemical functions of magnesium

Answer 6

Calcification of bones and teeth
Neuromuscular excitability
Enzyme action

Question 7

What does hypermagnesemia cause?

Answer 7

Reduced neuromuscular excitability

Question 8

What does hypomagnesemia cause?

Answer 8

Increased neuromuscular excitability
Chronic deficiency accompanied by hypocalcemia due to partial inhibition of PTH secretion

Hypomagnesemia commonly seen in ICU patients

Question 9

What are the sources of sulfur?

Answer 9

Methionine & cysteine

Question 10

In what form is sulfur absorbed?

Answer 10

Organic form

Question 11

What are the functions of sulfur?

Answer 11

Component of biologically active proteins - Insulin, Ig
Structure of cartilage & bone - Chondroitin sulphate
Sulfur containing amino acids at the active site of enzymes
Component of antioxidants (like Glutathione sulfhydryl group)
Detoxification of xenobiotics
Component of vitamins - Thiamine, biotin, pantothenic acid, lipoic acid

Question 12

Excretion of sulfur

Answer 12

Sulphur is oxidized to SO₄ in liver & excreted in urine
Urinary sulfate is made up of 3 fractions: Inorganic (80%), Organic (10%) and Unoxidised (10%)