vitamin Vitamins Oral

Vitamin B9

An essential B-vitamin for DNA synthesis, cell division, and healthy fetal development. The active form, methylfolate, is directly usable by the body.

Sci.Folate folate metafolin methylfolate vitamin b9 Vitamin B9 (methylfolate) folic acid 5-MTHF L-methylfolate
13 forms
Oral

About Vitamin B9

Vitamin B9, commonly referred to as folate, is a water-soluble B-vitamin family essential for nucleotide synthesis, DNA repair, methylation cycles, and cell division. It is critical during periods of rapid growth, such as pregnancy and fetal development. The family includes synthetic folic acid (used in fortification and supplements) and various naturally occurring folates found in foods like leafy greens, legumes, and liver. The active, metabolized forms in the body, such as 5-methyltetrahydrofolate (5-MTHF), are crucial for homocysteine metabolism and neurological function.

Official resources

Fact sheets from the NIH Office of Dietary Supplements related to this ingredient group.

Dietary Supplement Label Database

Ingredient group data in NutriNav is aligned with the NIH Dietary Supplement Label Database (DSLD).

DSLD group id
3299

At a glance

Suggested daily

400 mcg DFE for adults. Pregnant women: 600 mcg DFE.

Max safe daily

1000 mcg per day of folic acid from fortified foods and supplements (not applicable to natural folates from food).

Approval status

supplement

Compare All Forms

13 forms

Compare supplement forms of Vitamin B9 by absorption quality and what your body actually gets from each:

High Moderate Low
Form Absorption Steps to absorb Notes Action
5-Methyltetrahydrofolate (5-MTHF)
  • CAS: 118196-08-6
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Vitamin B9 (5-Methyltetrahydrofolate)
  • CAS: 118196-08-6
  • DSLD group id: 2510
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Vitamin B9 (Calcium Folinate)
  • CAS: 149-20-6
  • DSLD group id: 3314
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Vitamin B9 (calcium methylfolate)
  • CAS: 118196-55-6
  • DSLD group id: 9727
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Vitamin B9 (calcium methyltetrahydrofolate)
  • CAS: 151533-22-1
  • DSLD group id: 3522
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Vitamin B9 (Folate)
  • CAS: 59-30-3
  • DSLD group id: 2383
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Vitamin B9 (folic acid)
  • CAS: 59-30-3
  • DSLD group id: 3132
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Vitamin B9 (folic acid/folate)
  • CAS: 59-30-3
  • DSLD group id: 9728
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Vitamin B9 (folinic acid)
  • CAS: 151-11-1
  • DSLD group id: 8051
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Vitamin B9 (methylfolate)
  • CAS: 118-00-3
  • DSLD group id: 3251
  • Label category: Synthetic (Fermentation)
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Vitamin B9 (methyltetrahydrofolate)
  • CAS: 118196-08-6
  • DSLD group id: 3298
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Vitamin B9 (Mixed)
  • CAS: 59-30-3
  • DSLD group id: 3363
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Vitamin B9 (unspecified)
  • CAS: 59-30-3
  • DSLD group id: 4621
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Also appears on labels as

Additional names seen on supplement labels for forms of this ingredient (beyond the main aliases above).

(6s)-5-methylfolate, (6s)-5-methyltetrahydrofolate, (6s)-5-methyltetrahydrofolate acid, (6s)-5-methyltetrahydrofolic acid, (6s)-5-methyltetrahydrofolic acid, calcium salt, (6s)-5-mthf, (6s) 5-methyltetrahydrofolate, 5 methyltetrahydrofolate, 5'-methyltetrahydrofolic acid, 5-formyl-tetrahydrofolate, 5-formyl tetrahydrofolate, 5-formyltetrahydrofolate, 5-formyltetrahydrofolate calcium, 5-methyl-tetrahydrofolic acid, 5-methyletrahydrofolate, 5-methyl tetrahydrofolate, 5-methyltetrahydrofolate, 5-methyltetrahydrofolate biofolate, 5-methyltetrahydrofolate calcium, 5-methyltetrahydrofolate glucosamine salt, 5-MTHF Calcium Salt, 6(s)-5-methyltetrahydrofolic acid, arcofolin, biofolate, calcium-l-5-methyltetrahydrofolate, calcium 5-formyltetrahydrofolate, calcium 5-methyltetrahydrofolate, calcium folinate, calcium l-5' methyltetrahydrofolate, calcium l-5-methylfolate, calcium l-5-methyltetrahydrofolate, calcium l-methyltetrahydrofolate, coenzyme folic acid, controlled release citrate d-pteroylmonoglutamic acid, cultured folic acid, folacin, folate b9, folate complex, folic acid and 5-mthf, folic acid b-9, folic acid dicalcium phosphate, folic acid trituration, folinic acid, glucosamine salt, hemafolate, hemafolate(tm), l-5 methyltetrahydrofolate calcium salt, L-5-Methyltetrahydrofolate, levomefolic acid, liposomal vitamin b9, l methylfolate calcium, metafolin l-5-methyltetrahydrofolate, methyl folate, methyltetrafolate, organic folic acid, organic vitamin b9, orgen-fa, poten-zyme(r) foiic acid, poten-zyme(r) folic acid, pteroylglutamic acid, quatrefolate, quatrefolic, Vitamin B9 (Calcium Folinate), Vitamin B9 (calcium methylfolate), Vitamin B9 (calcium methyltetrahydrofolate), Vitamin B9 (Folate), Vitamin B9 (folic acid), Vitamin B9 (folinic acid), Vitamin B9 (methyltetrahydrofolate), Vitamin B9 (Mixed), Vitamin B9 (unspecified), vitamin b9 biob9, vitamin b9 biob9(tm), xolafin-b(tm), [6s]-5-methyltetrahydrofolic acid

Type: Vitamins

Organic compounds essential for normal growth and nutrition. Required in small quantities in the diet because they cannot be synthesized by the body.

Absorption: Fat-soluble vitamins require dietary fat for absorption. Water-soluble vitamins are generally well-absorbed but excess amounts are excreted.

Interactions: Some vitamins can interfere with medications. Fat-soluble vitamins can accumulate in the body.

Watch out for

Possible interactions or cautions — talk to a healthcare provider if unsure.

  • May interact with certain medications such as methotrexate and anticonvulsants, affecting their efficacy.

Potential Benefits

Benefits associated with Vitamin B9 forms:

Mood Regulation Cardiovascular Health Prenatal Health Supports DNA synthesis Promotes cardiovascular health Essential during pregnancy

And 11 more benefits...

Potential Side Effects

Side effects associated with Vitamin B9 forms:

Gastrointestinal Upset How serious: Mild Overstimulation How serious: Mild Allergic Reactions How serious: Mild Gastrointestinal disturbances How serious: medium Gastrointestinal issues How serious: medium Masking of vitamin B12 deficiency How serious: medium

And 2 more side effects...

What does the research say?

Numerous studies have shown that 5-MTHF is effective in improving folate status in individuals with deficiencies and may have benefits in reducing homocysteine levels, which is associated with cardiovascular health. Research indicates that it may also play a role in mental health and cognitive function.