From the Guidelines
Folate levels should be checked to diagnose or monitor folate deficiency, particularly in patients undergoing bariatric surgery, as folate supplementation may mask severe vitamin B12 depletion. According to the British Obesity and Metabolic Surgery Society guidelines 1, it is essential to check folate levels to identify potential deficiencies, which can be caused by malabsorption or non-adherence to daily multivitamin and mineral supplements. Some medications, such as anticonvulsants, sulfasalazine, and methotrexate, may also affect folic acid levels 1.
Key Points to Consider
- Folate deficiency can cause megaloblastic, macrocytic anemia, and may be masked by folate supplementation in patients with vitamin B12 deficiency 1
- Treatment of folic acid deficiency typically involves oral folic acid 5 mg daily for a minimum of 4 months, after excluding vitamin B12 deficiency 1
- Certain patient populations, such as those undergoing bariatric surgery, may require closer monitoring of folate levels due to increased risk of deficiency 1
Clinical Considerations
When checking folate levels, it is crucial to consider the potential causes of deficiency, such as malabsorption or medication use, and to exclude vitamin B12 deficiency before initiating treatment 1. By prioritizing the diagnosis and treatment of folate deficiency, clinicians can help prevent complications such as anemia and neurological problems, ultimately improving patient outcomes in terms of morbidity, mortality, and quality of life.
From the FDA Drug Label
Folate deficiency may result from increased loss of folate, as in renal dialysis and/or interference with metabolism (e. g. folic acid antagonists such as methotrexate); the administration of anticonvulsants, such as diphenylhydantoin, primidone, and barbiturates; alcohol consumption and, especially, alcoholic cirrhosis; and the administration of pyrimethamine and nitrofurantoin Doses greater than 0. 1 mg should not be used unless anemia due to vitamin B12 deficiency has been ruled out or is being adequately treated with a cobalamin.
You would check a folate (Vitamin B9) level to:
- Diagnose or rule out folate deficiency, which may be caused by various factors such as increased loss of folate, interference with metabolism, or certain medications
- Ensure safe administration of folic acid, as doses greater than 0.1 mg should not be used unless vitamin B12 deficiency has been ruled out or is being adequately treated 2 2
From the Research
Reasons to Check Folate Levels
- To protect against fetal neural tube defects during pregnancy, as folate (vitamin B9) is widely accepted to play a crucial role in preventing these defects 3, 4
- To identify and manage megaloblastic anemia, which can be caused by folate deficiency, and to differentiate it from vitamin B12 deficiency 5, 6
- To assess the risk of poor pregnancy outcomes, including low infant birthweight and developmental delays, which can be associated with inadequate maternal folate status 4, 7
- To monitor the effectiveness of folate supplementation and to adjust treatment as needed, particularly in cases where folic acid supplementation may pose health risks, such as in individuals with reduced hepatic transformation of folic acid 3
- To investigate the causes of anemia, as folate deficiency is a common cause of anemia, especially in individuals with inadequate diet, increased requirements, impaired absorption, or pharmacologic interactions 6