Folic_Acid_Flashcards
How is folic acid converted in the body?
Folic acid is converted to tetrahydrofolate (THF).
What are good sources of folic acid?
Green, leafy vegetables are a good source of folic acid.
What is the function of tetrahydrofolate (THF)?
THF plays a key role in the transfer of 1-carbon units (e.g., methyl, methylene, and formyl groups) to the essential substrates involved in the synthesis of DNA & RNA.
What are the causes of folic acid deficiency?
Phenytoin, methotrexate, pregnancy, alcohol excess.
What are the consequences of folic acid deficiency?
Macrocytic, megaloblastic anaemia, neural tube defects.
What is the recommended dose of folic acid for all women during pregnancy?
All women should take 400mcg of folic acid until the 12th week of pregnancy.
What is the recommended dose of folic acid for women at higher risk of conceiving a child with a neural tube defect (NTD)?
Women at higher risk should take 5mg of folic acid from before conception until the 12th week of pregnancy.
Who is considered at higher risk of conceiving a child with a NTD?
Women are considered higher risk if any of the following apply: either partner has a NTD, they have had a previous pregnancy affected by a NTD, they have a family history of a NTD, the woman is taking antiepileptic drugs or has coeliac disease, diabetes, or thalassaemia trait, or the woman is obese (BMI of 30 kg/m2 or more).
summarise folic acid
Folic acid
Folic acid is converted to tetrahydrofolate (THF). Green, leafy vegetables are a good source of folic acid.
Functions
THF plays a key role in the transfer of 1-carbon units (e.g. methyl, methylene, and formyl groups) to the essential substrates involved in the synthesis of DNA & RNA
Causes of folic acid deficiency:
phenytoin
methotrexate
pregnancy
alcohol excess
Consequences of folic acid deficiency:
macrocytic, megaloblastic anaemia
neural tube defects
Prevention of neural tube defects (NTD) during pregnancy:
all women should take 400mcg of folic acid until the 12th week of pregnancy
women at higher risk of conceiving a child with a NTD should take 5mg of folic acid from before conception until the 12th week of pregnancy
women are considered higher risk if any of the following apply:
either partner has a NTD, they have had a previous pregnancy affected by a NTD, or they have a family history of a NTD
the woman is taking antiepileptic drugs or has coeliac disease, diabetes, or thalassaemia trait.
the woman is obese (defined as a body mass index [BMI] of 30 kg/m2 or more).
A 33-year-old woman who is trying to conceive for the first time with her long term partner attends to see her GP to enquire as to whether there are any medications that she should be taking in preparation.
Her past medical history is insignificant, however her body mass index is 31kg/m². She is on no regular medications.
Which of the following medications should be prescribed?
Labetalol
Metformin
Folic acid 5mg OD
Folic acid 400mcg OD
Folic acid 800mcg OD
Folic acid 5mg OD
Pregnant obese women (BMI >30 kg/m2), should be given high dose 5mg folic acid
Pregnant women who have a BMI of >30kg/m2 should be given high dose folic acid 5mg OD from before conception until 12 weeks. These women are at higher risk of conceiving a child with neural tube defects.
Labetalol is used to treat hypertension in pregnancy.
Metformin can be used in the management of diabetes in pregnancy, however it is not indicated in this case.
Folic acid 400mcg OD is the dose given to all pregnant women who are not high risk of developing neural tube defects. It is taken until 12 weeks.
Folic acid 800mcg is not a dosage frequently used in pregnancy.
A 23-year-old patient with a history of well-controlled epilepsy presents to general practice with her partner. They have been trying to conceive with regular sexual intercourse for the past 11 months. Her current medications include omeprazole, levetiracetam, folic acid 400 micrograms and paracetamol as required.
What medication changes are most appropriate?
Start letrozole 2.5 milligrams
Start clomiphene 50 milligrams
Discontinue levetiracetam
Folic acid 5 milligrams
No medications required until >12 months of regular sexual intercourse
Folic acid 5 milligrams
Women on antiepileptics, who try to conceive, should receive folic acid 5mg instead of 400mcg OD
Important for meLess important
This patient is trying to conceive whilst on antiepileptic and so should receive a 5 milligrams of folic acid. Any women of childbearing potential taking any antiepileptic drug should receive 5 milligrams folic acid prior to conception and continue throughout pregnancy.
Letrozole 2.5 mg is used to stimulate ovulation in patients with polycystic ovary syndrome (PCOS). However, this patient has no such diagnosis and has only been trying to conceive for <12 months, therefore no investigation or management for infertility is required at this stage.
Similarly, clomiphene is used to stimulate ovulation in patients with PCOS which is inappropriate in this patient.
Adequate control of epilepsy is of mutual benefit to mother and foetus, with levetiracetam being one of the safer antiepileptics in pregnancy. Moreover, it is potentially dangerous to discontinue this medication and any medication changes should be made by a specialist.
Although it is true that no medications should be started for infertility before 12 months of regular intercourse, this patient is at risk of having a child with a neural tube defect due to her antiepileptic medication. Therefore, she should be started on a high dose of folic acid.
A 29-year-old woman presents to the GP surgery, reporting that she has just found out she is pregnant. She is delighted, and keen to proceed with the pregnancy.
She is 6 weeks by dates. She feels well and is currently asymptomatic. Her past medical history is unremarkable and she takes no regular medications. She doesn’t smoke, nor does she drink alcohol.
Body Mass Index (BMI) is 34 kg/m².
Blood pressure is 110/60 mmHg.
Urine dip is negative.
She has heard she needs to take some vitamin D and folic acid ‘supplements’ to maximise her chances of a healthy pregnancy. Which regimen would be most advisable in her case?
Vitamin D 400IU daily throughout the pregnancy, and folic acid 400microg daily for the first 12 weeks of pregnancy
Vitamin D 400IU daily throughout the pregnancy, and folic acid 5mg daily for the first 12 weeks of pregnancy
Vitamin D 400IU daily, and folic acid 400microg daily, both throughout the pregnancy
Vitamin D 400IU daily, and folic acid 5mg daily, both throughout the pregnancy
Vitamin D 400IU daily, and folic acid 5mg daily, both for the first 12 weeks of pregnancy
Vitamin D 400IU daily throughout the pregnancy, and folic acid 5mg daily for the first 12 weeks of pregnancy
Pregnant obese women (BMI >30 kg/m2), should be given high dose 5mg folic acid
All pregnant women should take vitamin D 400IU once daily, throughout the pregnancy.
In addition, pregnant women should also take folic acid daily for the first 12 weeks.
However, the dose of folic acid is dependent on whether there are risk factors present for the development of a neural tube defect, such as spina bifida - if there are no risk factors, the dose is 400 micrograms daily, if risk factors are present the dose is 5mg daily.
Maternal obesity (BMI >30 kg/m²) is one risk factor for a neural tube defect, hence this woman needs to take the higher dose of folic acid.
31-year-old woman presents with a positive urine pregnancy test. Blood tests are organised and lifestyle advice is given. She has no significant medical history. On examination, the following observations are noted:
Heart rate 94 beats per minute
Blood pressure 124/77 mmHg
Oxygen saturation 99% on room air
Temperature 36.5ºC
Respiratory rate 15 breaths per minute
BMI 31 kg/m²
What supplementation should be recommended for this woman?
Ferrous sulfate daily
Folic acid 0.4mg daily
Folic acid 5mg daily
Vitamin B12 daily
Vitamin D daily
Folic acid 5mg daily
Pregnant obese women (BMI >30 kg/m2), should be given high dose 5mg folic acid
This is a pregnant woman who is obese. She requires high-dose folic acid supplementation during pregnancy regardless of her medical history. This is important in preventing neural tube defects.
Iron supplementation may be required in a pregnant woman who has iron-deficiency anaemia. If suspected, the patient’s iron levels can be checked but at this stage, there is no requirement for this.
Low-dose folic acid supplementation would be considered in this case if this patient was not obese and would also be effective in preventing neural tube defects.
Vitamin B12 supplementation is required in pregnant women with B12 deficiency. If suspected, the patient’s B12 levels can be checked but at this stage, there is no requirement for this.
Vitamin D supplementation can also be required in pregnant women who have a deficiency. There is no indication in this case that the patient suffers from a deficiency and it is not worth checking unless she has risk factors like dark skin and modest clothing.
A 32-year-old pregnant lady is found to be anaemic 20 weeks gestation. A full blood count shows:
Serum Hb 104 g/L
MCV 104 fL
A blood film shows hypersegmented neutrophils. She has a past medical history of coeliac disease. What is the most likely cause of the anaemia?
Reticulocytosis
Iron deficiency
Thalassaemia
Folate deficiency
Anaemia of chronic disease
Folate deficiency
The full blood count demonstrates a macrocytic anaemia. The blood films suggests that the cause of the macrocytosis is a megaloblastic anaemia which can occur due to folate or B12 deficiency. Folic acid deficiency is common in pregnancy and this is therefore the most likely answer. The malabsorption associated with coeliac disease makes it particularly likely in this case.
