Cobalamin & Folate Flashcards
What causes megaloblastic anaemia?
I deficiency in vitamin B12 and folate
What is characteristic of megaloblastic anaemia?
Abnormally large megaloblasts and
Larger than normal macrocytic cells (red cells)
What are macrocytic cells?
Red cells
What might produce irreversible neurological disorders due to demyelination of nerves.
Deficiency of B12
What is requirements storage and defficiency of cobalamin B12
RNI (over 15 years) 1.2-1.5 micrograms
Liver can still come Alamine (five years)
Deficiency results in pernicious anaemia
Name 6 functions of vitamin B12
Synthesis of nucleic acids and DNA Involved in cell division RBC synthesis (with folate and iron) Nerve fibre; myelin sheath formation Fatty acid synthesis Energy production
What are megaloblasts?
Red cell precursors.
What does B12 required to be absorbed?
Intrinsic factor which is secreted mainly from the gastric parietal cells
What is the difference between folate and folic acid?
Folic acid is the oxidised form found in fortified foods and supplements.
Folate is the reduced form found naturally in foods and biological tissues.
Name sources of folate
Mushrooms, spinach, broccoli, asparagus.
What destroys folate?
Heat, oxidation and ultra violet light.
Which form must folate be reduced to before absorption?
Monoglutamate form
What is PCFT?
Proton-coupled folate transporter transports folate into intestinal cells.
What might mask the neurological damage caused by a vitamin B12 deficiency?
Folic acid supplements
Why does folic acid supplements mask vitamin B12 deficiency?
Because folic acid can alleviate the megaloblastic anemia, but. Neurological damage progresses undetected and is irreversible.
