Nutrition - B12, Folate

Question 1

B12
-causes of deficiency
-absorption

Answer 1

Most common - malabsorption
-pernicious anemia (parietal cells and IF destroyed)
-IBDs, Coeliac, atrophic gastritis
-surgery (gastrectomy, bypass, terminal ileum resectiom)

Not enough in diet - vg/v

Increased requirements
-pregnancy, breastfeeding
-hyperthyroid
-AIDS

Drug induced

BINDS TO IF IN STOMACH => ABSORBED IN TERMINAL ILEUM

Question 2

B12, folate
-deficiency presentation

Answer 2

B12
Anemia - SOB, tired, pale, glossitis
Neuro (subacute combined degeneration of SC - lemniscal and corticospinal)
-dorsal column affected before distal paraesthesia
Psychiatric - mood disturbances

Folate
Anemia without neuro signs

Question 3

B12 and folate
-investigations
-management

Answer 3

FBC, blood smear - macrocytic megaloblastic anemia
Serum B12, folate

B12 IM injection replacement/maintenance
Increase B12 intake - eggs, meat, dairy, fish, fortified/supplements

If drug induced => med review

Refer if
-neuro symptoms
-possible GI cause, malignancy

Folate supplements - IMPORTANT TO RULE OUT B12 DEFICIENCY AS FOLATE THERAPY CAN MASK NEURO SIGNS OF B12 DEFICIENCY
Increase folate intake - dark leafy veg
Manage underlying causes

Question 4

Folate
-causes of deficiency
-absorption

Answer 4

Phenytoin, methotrexate
Pregnancy
Alcohol excess

Malabsorption - eg. coeliac

Proximal small intestine - duodenum, jejunum