Folate
L-5-MTHF-Ca at 400 mcg DFE, the active form. High folate can mask a B12 shortfall on a blood count, which is why the two travel together.
Written by R. Kessler · About Knurle · Editorial policy
The short answer
Folate is a B vitamin needed for red blood cell formation and for homocysteine metabolism. L-5-methyltetrahydrofolate is the active form, and it is what circulates in the body, so it skips the MTHFR conversion step that folic acid requires.
The form, and why it matters
Folic acid is the synthetic oxidised form used in fortification and most supplements, and it needs conversion by MTHFR. L-5-MTHF calcium is the reduced active form. People with common MTHFR variants convert less efficiently, which is the reason to prefer the active form.
Typical dose
The adult reference intake is 400 mcg DFE a day, rising to 600 in pregnancy and 500 while breastfeeding. Keel carries 400 mcg DFE as the calcium salt of L-5-MTHF.
What the research shows
Folate and B12 work in the same pathway, and high folate intake can correct the anaemia of a B12 deficiency while leaving the neurological damage to progress. That interaction, rather than any standalone benefit, is why a formula carrying methylated B12 carries active folate beside it.
Who should be careful
Folic acid at high intakes can mask B12 deficiency anaemia. Do not take high-dose folate alongside a B12 supplement without knowing your B12 status, and tell your clinician about both.
Where it sits in our formulas
| Product | Form on the label | Amount per serving | % Daily Value |
|---|---|---|---|
| Keel | as L-5-MTHF-Ca | 400 mcg DFE | 100% |
Sources
Figures checked against the sources above on 21 September 2026.
Vitamin B12
Methylcobalamin at 525 mcg. Both forms raise B12; neither has been shown clearly better for topping up a dietary gap in a healthy adult.
Read itVitamin B6
Pyridoxal 5′-phosphate, the active form. Keel carries a high 26 mg because it sits inside a blend designed for people eating far less.
Read itIron
Ferrous bisglycinate at 18 mg, a chelated form that is usually kinder to the stomach than oxide or sulfate at the same elemental amount.
Read itMethylated B12, folate and B6: when form matters
Why methylcobalamin, L-5-MTHF-Ca and P5P instead of cyanocobalamin, folic acid and plain B6. Active forms, homocysteine, and the MTHFR story plainly told.
Read itEating less on a GLP-1? What runs low first
Appetite drops, portions shrink, and the multivitamin you took with breakfast may no longer cut it. Which vitamins people run low on during GLP-1 use, why absorption shifts, and what a single daily habit can sensibly cover.
Read itEvery milligram, printed.
Each amount on the label is the amount in a full daily serving, and it matches what is on this page.
