Pyridoxine revision questions - week 10

Question 1

Food sources

Answer 1

animal protein foods, potatoes, bananas, legumes

Question 2

Absorption

Answer 2

• present in food in the coenzyme form pyridoxal phosphate (PLP)
• converted to B6 for absorption
• animal source more readily absorbed
• passive diffusion in SI, can aso be taken in the coenzyme form if a lot is available

Question 3

Transport

Answer 3

• portal vein to liver

- active form PLP made in liver circulates bound to albumin

Question 4

Storage

Answer 4

muscle tissue is the main storage site

Question 5

Excretion

Answer 5

in urine

Question 6

Coenzyme form

Answer 6

pyridoxal phosphate (PLP)

Question 7

main function

Answer 7

Coenzyme in AA metabolism, haem synthesis, lipid metabolism and homocysteine metabolism

Question 8

RDI

Answer 8

19-50yrs - 1.3mg

>50yrs - men 1.7mg, women 1.5mg

Question 9

UL

Answer 9

100mg - based on nerve destruction

Question 10

Toxicity

Answer 10

• risk of permanent nerve damage (e.g. walking difficulties, peripheral neuropathy)
• only from supplements

Question 11

deficiency

Answer 11

Microcytic hypochromic anemia