Is a folate (folic acid) level of 2.2 nanograms per milliliter (ng/mL) within the normal range?

Folate Level of 2.2 ng/ml Assessment

A folate level of 2.2 ng/ml is below the normal range and indicates folate deficiency that requires treatment. According to clinical guidelines, serum folate levels below 5 ng/mL indicate folate deficiency, and levels below 2 ng/mL usually result in megaloblastic anemia 1.

Interpreting Folate Levels

The normal range for serum folate is typically:

• Deficiency: <3.0 ng/mL (<6.6 nmol/L) 2
• Borderline: 3.0-5.0 ng/mL
• Normal: 5.0-15.0 ng/mL 1

At 2.2 ng/ml, this value falls into the deficiency range and is very close to the critical threshold of 2.0 ng/ml, below which megaloblastic anemia typically develops 1.

Clinical Significance

Folate deficiency has several important clinical implications:

• Hematologic effects: Can lead to macrocytic/megaloblastic anemia
• Neurologic effects: May contribute to neurological symptoms when combined with B12 deficiency
• Homocysteine levels: Folate levels under 8 μg/L (18 nmol/L) are associated with elevated homocysteine, a cardiovascular risk factor 3

Recommended Management

1. Initiate oral folic acid supplementation at 1 mg daily for 3 months 4

   • This is the standard treatment dose for folate deficiency
   • Higher doses (up to 5 mg daily) may be needed for specific populations

2. Evaluate for underlying causes:

   • Inadequate dietary intake
   • Malabsorption (celiac disease, inflammatory bowel disease)
   • Increased requirements (pregnancy, hemolytic anemia)
   • Medications that interfere with folate metabolism (methotrexate, certain anticonvulsants)

3. Check additional laboratory tests:

   • Complete blood count to assess for macrocytic anemia
   • Vitamin B12 levels (folate and B12 deficiencies can coexist) 4
   • Consider homocysteine levels as a functional marker of folate status 5

4. Follow-up monitoring:

   • Repeat serum folate measurement within 3 months after supplementation to verify normalization 4
   • Monitor complete blood count to assess resolution of anemia if present

Important Considerations

• Serum folate reflects recent dietary intake, while red blood cell folate better reflects long-term status and tissue stores 5
• Vitamin C improves folate bioavailability by limiting degradation in the stomach 5
• Since mandatory folic acid fortification of enriched cereal grains in the United States (1998), the prevalence of folate-deficiency anemia has decreased dramatically 2
• Folate deficiency can mask B12 deficiency by correcting the hematologic abnormalities while allowing neurological damage to progress

Dietary Sources of Folate

To maintain adequate folate levels after treatment:

• Pulses (legumes): 200-300g covers daily requirements
• Leafy green vegetables: 400g covers daily requirements
• Eggs, nuts, and whole grain products 5

Remember that food folates have lower bioavailability than synthetic folic acid, so dietary folate equivalent (DFE) calculations may be needed for precise nutritional planning 5.