menadione sodium bisulfite complex

VitaminCaution for dogsCaution for cats

Menadione is synthetic vitamin K3 — the one vitamin the engine flags, for a questioned safety margin and the existence of quieter alternatives.

Also appears on labels as: menadione · vitamin k3 · menadione sodium bisulfite · menadione dimethylpyrimidinol bisulfite · menadione sodium bisulfite complex (source of vitamin k activity)

What it is

A synthetic vitamin K precursor (K3), stable and cheap where natural K1 (phylloquinone) is neither. The safety literature questions K3's margin at high doses — older concerns from other species and injectable use — while evidence of harm at feed inclusions is thin. What tilts the judgment is need: healthy dogs and cats synthesize vitamin K via gut flora and rarely require supplementation at all, making K3's presence optional risk rather than necessary risk.

Why it's in pet food

Cost and stability. Natural K1 is expensive and degrades in processing; menadione survives manufacturing at pennies. Many complete foods include no vitamin K source whatsoever and pass feeding trials — which is the strongest quiet argument that the cheap insurance isn't buying much.

How Bowlmark scores it

Scores are deterministic math over the printed label — the rules below apply to every product identically, and nothing estimates or fills in a blank.

The vitamin aisle's one flag: menadione in any wording — including the reassuring '(source of vitamin K activity)' phrasing — takes a −15 warn deduction for both species. The flag encodes precaution plus available alternatives, not proven feed-dose harm, and this page says so plainly: a food is not poisoned by menadione; it has simply made a choice the engine prices.

Read the full methodology

Common questions

Answers come from this entry and the scoring rules above — reviewed before publish, like everything else on this page. For anything about your own pet, your vet knows best.

Is menadione (vitamin K3) harmful to dogs and cats?

The safety literature questions K3's margin at high doses, while evidence of harm at feed inclusions is thin. What tilts the judgment is need: healthy dogs and cats synthesize vitamin K via gut flora and rarely require supplementation at all, making menadione's presence optional risk rather than necessary risk. A food is not poisoned by it; it has simply made a choice the engine prices.

Why use menadione instead of natural vitamin K?

Cost and stability: natural K1 (phylloquinone) is expensive and degrades in processing, while menadione survives manufacturing at pennies. Many complete foods include no vitamin K source whatsoever and pass feeding trials — the strongest quiet argument that the cheap insurance isn't buying much.

How does Bowlmark score menadione?

It is the vitamin aisle's one flag: menadione in any wording — including the reassuring "(source of vitamin K activity)" phrasing — takes a 15-point warning deduction for both species. The flag encodes precaution plus available alternatives, not proven feed-dose harm.

Foods that list menadione sodium bisulfite complex

Ranked by score where scores exist. Placement here is never sold.

Compare foods that list menadione sodium bisulfite complex

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Sources

Cite this page

Bowlmark. "Menadione sodium bisulfite complex in pet food — what it is and how it scores." https://www.bowlmark.com/ingredient/menadione-sodium-bisulfite-complex

Engine: Methodology engine v1.1.0 · config 13c99e2f
Verified: Last verified August 21, 2026

No stored score to stamp yet — the engine and config above are the ones a scan runs today.

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