Symptoms of Folate Deficiency in Adults
The primary symptoms of folate deficiency in adults include megaloblastic anemia, neuropsychiatric manifestations, and gastrointestinal disturbances, with megaloblastic anemia being the most common clinical presentation.
Hematological Manifestations
- Megaloblastic anemia - characterized by macrocytic red blood cells and abnormal white blood cell development 1, 2
- Pancytopenia - reduction in all blood cell lines (in severe cases) 3
Neuropsychiatric Manifestations
- Depression and irritability 1, 4
- Cognitive impairment and psychosis 1
- Insomnia and fatigue 1, 4
- Peripheral neuropathy with numbness and tingling of limbs 4, 5
- Restless legs syndrome 4, 5
- Impaired coordination 4
- Muscular pain and permanent muscular fatigue 5
Gastrointestinal Manifestations
- Glossitis (inflammation of the tongue) 1
- Angular stomatitis (inflammation at corners of the mouth) 1
- Oral ulcers 1
- Malabsorption issues 2
- Constipation (can be long-lasting) 5
Other Manifestations
- Increased risk of occlusive vascular disease and thrombosis due to hyperhomocysteinemia 2
- Impaired immune function 2
- Potentially increased risk of neoplasia 2
Special Considerations
Pregnancy
- Folate deficiency during pregnancy is associated with:
Relationship with Vitamin B12 Deficiency
- Symptoms of folate deficiency often overlap with vitamin B12 deficiency 1
- Important: Always check for vitamin B12 deficiency before treating folate deficiency, as folate supplementation can mask B12 deficiency while neurological damage progresses 1
- Folate deficiency is often related to vitamin B12 deficiency, as B12 plays a role in folate metabolism 1
Diagnostic Considerations
- Serum folate levels below 10 nmol/L indicate folate deficiency 1
- Levels below 2 ng/mL usually result in megaloblastic anemia 6
- Red blood cell folate below 340 nmol/L indicates deficiency 1
- Homocysteine levels may be elevated 1
Risk Factors
- Poor dietary intake 1
- Malabsorption conditions 1
- Drug interactions (anticonvulsants, sulfasalazine, methotrexate) 1
- Alcoholism 4
- Bariatric surgery 1
- Older age 1
Treatment Approach
- For mild to moderate deficiency: oral folic acid supplementation of 1-5 mg daily 1, 4
- For severe deficiency with clinical manifestations: oral folic acid 5 mg daily for a minimum of 4 months 1
- Always rule out vitamin B12 deficiency before starting folate treatment 1
- Address underlying causes (improve diet, review medications, treat malabsorption) 1
Clinical Pitfalls
- Folate deficiency can occur without megaloblastic anemia 2, 5
- Neurological symptoms may appear before hematological changes 4
- Treating folate deficiency without checking B12 status can worsen neurological damage in B12-deficient patients 1
- Some patients may require long-term supplementation, especially those with chronic conditions affecting absorption 1