Folate

B vitamin important for cell division and DNA synthesis

12/22Providers
Vitamins &NutrientsCategory
>3.0 ng/mL, Optimal:Reference
Widely Available

12 of 22 providers

Category

Vitamins &Nutrients

Reference Range

>3.0 ng/mL, Optimal:7-15 ng/mL

What is Folate?

Folate (vitamin B9) is a water-soluble vitamin essential for DNA synthesis, cell division, methylation, and red blood cell formation. The term "folate"refers to the natural form found in foods (leafy greens, legumes, citrus), while "folic acid"is the synthetic form used in supplements and fortified foods. Folate is critical during periods of rapid cell division—pregnancy, infancy, adolescence—and deficiency causes neural tube defects (spina bifida) in developing fetuses, which is why folic acid fortification of grain products has been mandatory in the US since 1998.

Here's the critical insight:not all folate is created equal. Folic acid (synthetic) must be converted to the active form, 5-methyltetrahydrofolate (5-MTHF or methylfolate), via the MTHFR enzyme. ~40% of people have MTHFR gene variants (C677T or A1298C) that reduce enzyme activity by 30-70%, impairing folic acid metabolism. These individuals may have normal serum folate but functional deficiency at the cellular level. Methylfolate supplements bypass this issue entirely and are preferred, especially for those with MTHFR variants, depression, or cardiovascular disease.

Folate works in tandem with B12 in the methylation cycle, converting homocysteine→methionine. Deficiency of either vitamin causes elevated homocysteine (>10 mcmol/L), a risk factor for cardiovascular disease, stroke, cognitive decline, and Alzheimer's. If folate is low but B12 is also low, you MUST correct B12 first—giving folate alone can mask B12 deficiency anemia while allowing irreversible neurological damage to progress.

Why Folate Matters for Longevity

  • DNA synthesis and cell division:Folate is required for synthesis of purines and pyrimidines (building blocks of DNA). Deficiency impairs rapidly dividing cells, causing megaloblastic anemia.
  • Methylation cycle:Folate (as 5-MTHF) is the methyl donor for homocysteine→methionine conversion. Adequate folate lowers homocysteine, reducing CVD and stroke risk.
  • Neural tube defect prevention:Folate is critical in first 28 days of pregnancy for neural tube closure. Deficiency causes spina bifida, anencephaly. Folic acid supplementation (400-800 mcg) reduces NTD risk by 70%.
  • Cardiovascular health:Folate lowers homocysteine, protecting against atherosclerosis, heart attack, and stroke. Low folate associated with 30-50% higher CVD risk.
  • Brain health and mood:Folate supports neurotransmitter synthesis (serotonin, dopamine). Deficiency linked to depression (especially treatment-resistant depression), cognitive decline, dementia.
  • Cancer prevention (controversial):Adequate folate may protect against colorectal cancer by supporting DNA repair and methylation. However, excessive folic acid supplementation (>1000 mcg) may promote existing cancers.

Optimal vs Standard Ranges

Optimal (Longevity)
>20 ng/mL▼
  • Target for optimal methylation, brain health, CVD prevention
  • Many functional medicine doctors target >15-20 ng/mL
Adequate (Standard)
>10 ng/mL▼
  • Meets standard guidelines
  • Sufficient to prevent megaloblastic anemia but may be suboptimal for methylation and homocysteine
Suboptimal
4-10 ng/mL▼
  • Low-normal
  • May have elevated homocysteine
  • Consider supplementation, especially if MTHFR variant or CVD risk factors
Deficient
<4 ng/mL▼
  • Frank deficiency
  • Causes megaloblastic anemia, elevated homocysteine, increased NTD risk in pregnancy
  • Requires immediate folate supplementation
Standard lab range: >3.0 ng/mL, Optimal:7-15 ng/mL
Sources:PMID:38950416, PMID:27528407, PMID:34929527

Scientific Evidence

Dietary insufficiency:Low intake of leafy greens, legumes, citrus, fortified grains.|Malabsorption:Celiac disease, Crohn's disease, tropical sprue, bacterial overgrowth (SIBO).|Medications:Methotrexate (chemotherapy, rheumatoid arthritis), sulfasalazine, anticonvulsants (phenytoin), metformin.|Alcohol abuse:Impairs folate absorption and increases excretion.|MTHFR gene variants:C677T or A1298C reduce folic acid conversion to active form, causing functional deficiency despite normal serum folate.|Pregnancy and lactation:Increased folate requirements (600-800 mcg/day). Deficiency increases NTD risk.|Chronic hemolytic anemia:Increased cell turnover consumes folate (sickle cell, thalassemia).

Excessive folic acid supplementation (>1000 mcg/day). Natural folate from food cannot cause toxicity.|Fortified foods + supplements:Easy to exceed 1000 mcg/day if consuming fortified grains + multivitamin + B-complex.|Rarely, kidney disease (impaired excretion).

Source:Baseline:Check serum folate if symptoms (fatigue, anemia, depression) or risk factors (low vegetable intake, malabsorption, alcohol use, MTHFR variant).|Check homocysteine:More sensitive marker of functional folate status. If homocysteine >10 mcmol/L, consider folate (and B12) deficiency even if serum folate appears normal.|After starting supplementation:Retest folate and homocysteine in 3 months. Goal:folate >15 ng/mL, homocysteine <8 mcmol/L.|Pregnancy:Baseline folate before conception. Supplement 400-800 mcg/day throughout pregnancy.|If on methotrexate:Monitor folate closely;may need leucovorin (folinic acid) rescue to prevent toxicity. (PubMed)

Folate and Neural Tube Defects

Folic acid supplementation (400-800 mcg/day) started before conception reduces NTD risk by 70%. US grain fortification (since 1998) reduced NTD prevalence by 25-30%. Neural tube closes by day 28 of pregnancy—before most women know they're pregnant—hence recommendation for all women of childbearing age to supplement.

Source:MRC Vitamin Study Research Group. Prevention of neural tube defects with folic acid. Lancet. 1991;338(8760):131-137. (PubMed)

Folate and Homocysteine/CVD

Folate supplementation lowers homocysteine by 25-30%. Meta-analyses show folic acid supplementation (800 mcg/day) reduces stroke risk by 10-20%, with greater benefit in populations without grain fortification. CVD benefit is modest in RCTs, possibly because started too late in disease process or because homocysteine is a marker, not a cause.

Source:Wang X, et al. Efficacy of folic acid supplementation in stroke prevention:a meta-analysis. Lancet. 2007;369(9576):1876-1882. (PubMed)

Folate and Depression

Folate deficiency is common in depression (15-40% of depressed patients have low folate). Low folate associated with poor antidepressant response. Methylfolate (15 mg/day) improves treatment-resistant depression when added to SSRIs in RCTs. Methylfolate enhances serotonin, dopamine, and norepinephrine synthesis.

Source:Papakostas GI, et al. L-methylfolate as adjunctive therapy for SSRI-resistant major depression. Am J Psychiatry. 2012;169(12):1267-1274.

Folate and Cognitive Decline

Low folate (<10 ng/mL) associated with 2-3x higher dementia risk. Folate + B12 + B6 supplementation slows cognitive decline and brain atrophy in elderly with elevated homocysteine. Benefits greatest when started early (MCI stage) before significant dementia.

Source:Durga J, et al. Effect of 3-year folic acid supplementation on cognitive function in older adults. Lancet. 2007;369(9557):208-216.

Which Providers Test Folate?

Superpower
Included in panel
Blueprint
Included in panel
Mito Health
Included in panel
Function
Included in panel
Marek Comp.
Included in panel
Marek Complete
Included in panel
Marek Exec.
Included in panel
Empirical Health
Included in panel
SiPhox Health
Included in panel
Hims Adv.
Included in panel
Vitality Std
Included in panel
Vitality Elite
Included in panel

Full Provider Comparison

ProviderIncludesAnnual CostBiomarkers
SuperpowerSuperpower✓$199100+ (150 with ratios)
WHOOP Advanced LabsWHOOP Advanced Labs—$34965
Labcorp OnDemandLabcorp OnDemand—$39830+
Life ExtensionLife Extension—$48640+
EverlywellEverlywell—$444288
Mito HealthMito Health✓$349100+
InsideTrackerInsideTracker—$76154
Function HealthFunction Health✓$365160+
Marek Health BaseMarek Health Base—$25065
Marek Health ComprehensiveMarek Health Comprehensive✓$49570+
Marek Health CompleteMarek Health Complete✓$895100+
Marek Health ExecutiveMarek Health Executive✓$1950150+
BlueprintBlueprint✓$37580+
Quest HealthQuest Health—$Varies75+
Empirical HealthEmpirical Health✓$190100+
Oura Health PanelsOura Health Panels—$9950
SiPhox HealthSiPhox Health✓$12460
Hims Labs BaseHims Labs Base—$19950
Hims Labs AdvancedHims Labs Advanced✓$499120+
HealthspanHealthspan—$418870-80+
Vitality Blueprint StandardVitality Blueprint Standard✓$37585
Vitality Blueprint EliteVitality Blueprint Elite✓$700128

Related Biomarkers

These biomarkers are often tested together with Folate or provide complementary health insights:

Vitamin B12 Homocysteine MCV, MCH, MCHC
Why test together: B12 (deficiencies can mask each other)

Frequently Asked Questions

What is Folate?

B vitamin important for cell division and DNA synthesis

What is the optimal range for Folate?

The standard reference range for Folate is >3.0 ng/mL, Optimal:7-15 ng/mL. Optimal ranges may differ based on individual health goals and expert recommendations.

Which blood test providers include Folate?

12 out of 22 blood testing providers include Folate in their panels. This biomarker is widely available across major providers.

What category does Folate fall under?

Folate is categorized under Vitamins &Nutrients. This category includes biomarkers that help assess related aspects of health and wellness.

Medical Disclaimer

This information is for educational purposes only and is not medical advice. Always consult with a qualified healthcare provider about your specific health needs.

Last reviewed:2026-02-20