B12 & Folate

Question 1

folate and B12 important in synthesis of …

Answer 1

DNA in RBC

Question 2

haemotological presentations of vitamin B12 and folate deficiencies are …

Answer 2

almost identical

Question 3

clinical difference is that B12 causes ____ whereas folate does not

Answer 3

neuropathy

Question 4

what are vitamins?

Answer 4

micronutrients essential for health which cannot be made in the body so must be acquired from food or supplemets

Question 5

two types of vitamin

Answer 5

• nine water soluble vitamins
• four fat soluble vitamins

Question 6

vitamins Bs & Cs

Answer 6

• excess excreted in urine
• not stored except B9,12
• deficiency can occur
• easily absorbed from diet

Question 7

vitamins DAKE

Answer 7

• not excreted in urine
• stored in fat
• unlikely to have deficiency
• can be toxic
• absoption depends on gut and pancreas

Question 8

sources of B12

Answer 8

• cheese
• eggs
• fish
• beef
• yoghurt

Question 9

B12 often called

Answer 9

Cobalamin

Question 10

daily requirement of B12

Answer 10

1 - 2 micrograms

Question 11

daily requirement of B12 for pregnancy

Answer 11

3 - 4 micrograms

Question 12

half life of B12 when stored in liver

Answer 12

12 months

Question 13

main loss of B12 from the body is via …

Answer 13

bile ( although half of it can be reabsorbed )

Question 14

medicines that can interfere with absorption, metabolism of storage of B12

Answer 14

• H2 blockers
• neomycin
• metformin

Question 15

abosrption of B12

Answer 15

• B12 attached to animal protein
• cut and chewed by teeth + mixed with saliva
• salvia contains R-binder that protects B12 from acids
• pepsin seperates B12 from meat + then binds to R-binder
• pancreatic proteases seperate B12 from R-binder then binds to IF
• in blood of portal vein 20% B12 combines with transcobalamin 2 and goes to body tissues
• IF receptors on apical surface of ileal cells collect IF &B12 and bring into cells
• remaining B12 circulates with transcobalamin 1 - not available to body cells

Question 16

B12 signs & symptoms - haemotological

Answer 16

anaemia ( macrocytic )

Question 17

B12 signs & symptoms - neurological ( periph )

Answer 17

• parathesia
• muscle weakness
• loss of proprioception
• headache

Question 18

B12 signs & symptoms - neurological ( central )

Answer 18

• poor memory
• dementia
• depression

Question 19

B12 signs & symptoms - physiological

Answer 19

• smooth tongue
• weight loss
• reduced apetite

Question 20

folate refers to all forms of …

Answer 20

folic acid

Question 21

folate is a substrate for…

Answer 21

thymidine

Question 22

which vitamin is folate?

Answer 22

B9

Question 23

folate abundant in what foods

Answer 23

• leafy greens
• liver
• kidney
• yeast

Question 24

daily requirement of folate

Answer 24

100 - 200 mg

Question 25

folate - jejunum

Answer 25

50% absorbed in upper jejunum

Question 26

folate lost in -

Answer 26

• urine
• bile
• desquamating skin & intestines

Question 27

folate deficiency can cause

Answer 27

• spina bifida
• neural tube defects

Question 28

functions of folate

Answer 28

• helps tissues grow
• helps form red blood cells
• helps produce DNA
• works with B12 + vitamin C to help body break down, use and create new proteins

Question 29

causes of folate deficiency

Answer 29

• alcohol
• haemolytic diseases
• malabsorption
• anticonvulsant medicines
• B12 deficiency

Question 30

why should B12 deficiency be corrected before starting folate treatment?

Answer 30

because B12 deficiency can cause irreversible neurological disease