Vitamin B9 - Folate Metabolism and Deficiency

Question 1

Another name of folic acid or folate

Answer 1

Vitamin B9

Question 2

Source of folic acid/folate

Answer 2

• Leafy green vegetables,
• Citrus fruits
• Dry beans
• Nuts
• Yeasts
• Fortified cereals
• Liver

Question 3

Synthesis of folic acid

Answer 3

Gut bacteria

Question 4

Site of absorption of folic acid

Answer 4

Duodenum/ Proximal jejunum

Question 5

Duration of storage of folic acid in the body

Answer 5

4 months

Question 6

Effect of maternal folate deficiency in a pregnant mother

Answer 6

Foetal neural tube defects

Question 7

Causes of folate deficiency

Answer 7

Poor diet:

• Poverty
• Alcoholism
• Elderly

Malabsorption:

• Coeliac disease
• Tropical sprue

Increased demand:

• Pregnancy

increased Cell turnover:​

• Haemolysis
• Malignancy
• Haemolytic disease
• Renal dialysis

Alcohol

Drugs: (given in the drug causes)

Question 8

Name the drugs that interfere with folate metabolism (= inhibits dihydrofolate reductase)

Answer 8

• Methotrexate
• Azathioprine
• Pyrimethamine
• Trimethoprim

Question 9

Name the drugs that reduces folate absorption ( = reduces folate storage)

Answer 9

• Phenytoin
• Na valproate
• Primidone
• COCP

Question 10

Management of folate deficiency in male and non-pregnant female

Answer 10

• Assess for underlying cause
• Folic acid 5mg/day PO for 4months
• Never without B12 (unless B12 levels are completely normal)

Because if in a low B12 level state >>> if we only give folic acid >>> it precipitates/worsens subacute combined degeneration of spinal cord

Question 11

Management of folate deficiency in pregnancy

Answer 11

• ​Prophylactic dose of folate: 400mcg/day
• Given from conception until 12weeks at least

It prevents spinal bifida & anaemia

Question 12

Effect of folate deficiency

Answer 12

Megaloblastic macrocytic anaemia

Foetal neural tube defect