Folinic Acid (Calcium Folinate)
Also known as: calcium folinate, leucovorin, 5-formyltetrahydrofolate, 5-formyl-THF, citrovorum factor
Folinic acid (5-formyltetrahydrofolate) is a reduced, metabolically active folate supplied as its calcium salt. Unlike folic acid it does not require dihydrofolate reductase, and unlike L-5-MTHF it enters the folate cycle upstream of the MTHFR step, so it can feed both methylation and nucleotide synthesis. Its high-dose calcium salt is the drug leucovorin. As a supplement ingredient it appears in specialty folate, methylation, and neurodevelopment-support formulas, with randomized trials in children using much larger, physician-directed doses.
Research summary
Converted to 5,10-methenyl-THF and then to other tetrahydrofolate cofactors for purine, thymidylate, and methionine synthesis without needing DHFR or MTHFR.
Dosage
Daily amounts, of compound.
| Lowest studied | Typical range | Highest studied | Upper limit |
|---|---|---|---|
| 400 mcg | 400–800 mcg | 1,000 mcg | 1,000 mcg |
NIH ODS — UL of 1,000 mcg/day is set for folic acid from supplements and fortified foods; applied to this synthetic folate form as a conservative ceiling
Doses are mcg calcium folinate as labeled. Supplement-level amounts of 400 to 800 mcg mirror folic acid practice rather than a dose-finding trial of this form, and the same 400 mcg DFE DV framework applies (labelers generally use the 1.7 factor or a supplier-established one). dose_max_studied is capped at the UL; a 12-week randomized trial in children with autism used 2 mg/kg/day up to 50 mg/day under medical supervision, which is a drug regimen. Pair with vitamin B12.
Standardization: ≥97% calcium folinate (USP); supplied neat or as 1% dilutions
Source material: synthetic
As supplied: Often used as a 1% dilution on a carrier for microgram doses (0.1 mg powder per mcg); neat salt at mg doses. Supplier dependent.
Forms of Folate
| Form | Typical dose | Element % | Formats | Price |
|---|---|---|---|---|
| Folinic Acid (Calcium Folinate) | 400–800 mcg | — | Capsule, Tablet, Powder, Liquid | high |
| Folic Acid | 400–800 mcg | — | Capsule, Tablet, Powder, Gummy, Liquid, Softgel | low |
| L-5-Methyltetrahydrofolate (L-5-MTHF) | 400–1,000 mcg | — | Capsule, Tablet, Powder, Gummy, Liquid, Softgel | high |
Format suitability
- Capsule
- Powder
- Tablet
- Softgel
- Gummy
- Liquid
Light-sensitive; keep in opaque packaging. Rarely used in gummies.
Formulation notes
Leucovorin is used clinically to counter methotrexate and to potentiate fluorouracil, so any folinic acid product needs an interaction caution for those drugs. Pair with B12.
- Has an upper limit
- Notable drug interactions
Sources
Related ingredients
Folic Acid
VitaminFolic acid is the fully oxidized, synthetic form of folate used in food fortification and most supplements.
Typical: 400–800 mcg
L-5-Methyltetrahydrofolate (L-5-MTHF)
VitaminL-5-methyltetrahydrofolate is the main circulating form of folate and the form cells use directly for homocysteine remethylation, so it bypasses the MTHFR enzyme step that is less active in people carrying the common 677C>T variant.
Typical: 400–1,000 mcg
Vitamin D3 (Cholecalciferol)
VitaminThe form of vitamin D the body makes from sunlight and the most effective supplemental form for raising blood levels.
Typical: 1,000–2,000 IU
Calcium Carbonate
MineralThe most concentrated and least expensive common calcium salt, supplying about 40% elemental calcium by weight.
Typical: 250–600 mg
Vitamin B12 (Cyanocobalamin)
VitaminCyanocobalamin is the synthetic, highly stable form of vitamin B12 used in most supplements and fortified foods.
Typical: 100–1,000 mcg