Things to note:
- Dietary modifications to ensure adequate intake of folate and vitamin B12.
- Identify and treat the underlying cause, e.g. antibiotics for intestinal overgrowth with bacteria.
- After blood samples for RBC, folate and vitamin B12 levels have been taken, start with folic acid and vitamin B12.
- Monitor serum potassium and replace if necessary.
- Give vitamin B12 and folic acid together until the test results are available as giving folic acid alone in patients with a B12 deficiency may precipitate a permanent neurological deficit.
Adjust management according to results.Folic acid deficiency
Vitamin B12 deficiency
- Folic acid, oral, 5 mg daily until haemoglobin returns to normal.
- Prolonged treatment may be required for malabsorption states.
- Vitamin B12, IM.
- 1 mg daily for 5 days, then weekly for a further 3 doses.
- Follow with 1 mg every second month for life in patients with pernicious anaemia, except in patients with clearly modifiable nutritional deficiency.
Response to treatment is associated with an increase in strength and improved sense of well-being.
Reticulocytosis begins 3-5 days after therapy and peaks at about day 7.The anaemia is corrected within 1-2 months. The white cell count and platelets normalise in 7-10 days. As there is an increase in red blood cell production, short-term iron and folic acid supplementation is also recommended.
Consider the following if there is failure to respond:
- Co-existing folate and/or iron deficiency,
- Incorrect diagnosis,and
- Drug-induced, e.g. hydroxyurea, stavudine and zidovudine.
Vitamin B12 is indicated for patients after total gastrectomy or ileal resection.
- Vitamin B12, IM, 1 mg every second month for life.
Indications for folic acid:
- Chronic inherited haemolytic anaemias, e.g. sickle cell anaemia, thalassaemia.
- Myeloproliferative disorders.
- Exfoliative skin disorders.
- Increased demands, e.g. pregnancy, chronic haemodialysis.
- Folic acid, oral, 5 mg daily.