NutriStack
Vitamin B12 and Vitamin B9, a synergy.
B9 (folate) and B12 work together in the methionine cycle. B12 deficiency can be masked by high folate intake.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.
From the interaction database
What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Substances
- Vitamin B12 and Vitamin B9
- Pair type
- Synergy
- Evidence (highest tier)
- Strong
- Source citations
- 1 source
- Stack Score effect
- +2 to your Stack Score (per scored synergy row).
- Scope
- Supplement × Supplement
- Last verified
- May 30, 2026
Synergy · Strong evidence
Synergy
What is happening. B9 (folate) and B12 work together in the methionine cycle. B12 deficiency can be masked by high folate intake.
Mechanism. B12 is a cofactor for methionine synthase, which uses 5-methylTHF (from folate) to remethylate homocysteine. Without B12, folate becomes trapped as 5-methylTHF (methyl trap).
Recommendation. Always supplement B12 when taking folate. B12 deficiency with high folate can cause irreversible neurological damage if undetected.
Sources (1)
Stack Score
How this pair moves the number.
Effect on the composite score
If both Vitamin B12 and Vitamin B9 are in the same stack, this pair applies +2 to your Stack Score (per scored synergy row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
Check your full routine
One pair was the worked example. NutriStack runs every pair in your stack at once.
Drop in your supplements and prescriptions and the public database surfaces every interaction, synergy, timing rule, and contraindication, every one linked to its primary source.