PrometheusGeneral

Folate (B9) and Vitamin B12

Each entry’s own grades, side by side. A grade says how strong the evidence is for one outcome — it does not rank one entry over the other.

Compound or practice

Folate (B9)

Prevents neural-tube defects — the one supplement with an unambiguous public-health mandate before and in early pregnancy.

Grade A3 graded outcomesrevised Jul 10, 2026

A structured monograph in Prometheus's bundled library. Its grades are the monograph's own reading of the evidence, not a peer-reviewed review.

Compound or practice

Vitamin B12

Non-negotiable for plant-based diets and older adults — deficiency is quiet until it's neurological.

Grade A3 graded outcomesrevised Jul 10, 2026

A structured monograph in Prometheus's bundled library. Its grades are the monograph's own reading of the evidence, not a peer-reviewed review.

Swap the two

Graded in both

Outcomes are matched by name. Two entries can describe the same outcome in different words, so one listed further down may still be graded in the other.

No outcome has the same name in both entries. They may still overlap under different wording — read the two lists below.

Graded only in Folate (B9)

  • Neural-tube defect prevention Large effectEvidence grade A
  • Homocysteine lowering Moderate effectEvidence grade A
  • Cardiovascular events Trivial effectEvidence grade D

Graded only in Vitamin B12

  • Correcting deficiency / anemia Large effectEvidence grade A
  • Neuropathy (early deficiency) Moderate effectEvidence grade A
  • Energy in replete people Trivial effectEvidence grade D

Conditions

Only in Folate (B9)

None.

Only in Vitamin B12

What each entry says about the other

  • Folate (B9)’s entry · Caution: Folate can mask B12-deficiency anemia; assess B12 alongside.
  • Folate (B9)’s entry · Watch with: Folate can mask B12-deficiency anemia; assess B12 alongside.
  • Vitamin B12’s entry · Caution: High folate masks the anemia of B12 deficiency while nerve damage continues — check B12 directly.
  • Vitamin B12’s entry · Watch with: High folate masks the anemia of B12 deficiency while nerve damage continues — check B12 directly.

Both columns are read from the entries as they stand in this library. A comparison is not advice to take either one, and it is no substitute for a clinician who knows the person.