Menadione (vitamin K3)
الميناديون (فيتامين K3)
Synthetic vitamin (controversial) · CAS: 58-27-5 (menadione)
Permitted in pet food, banned in human supplements
Why this verdict
Synthetic vitamin K3. FDA removed menadione from HUMAN supplements over high-dose toxicity (oxidative RBC damage/hemolysis, hepatic/renal). In PET food: a 2021 AAFCO expert panel recommended MSBC as a safe and suitable source of vitamin K activity for all animals per GMP, and FDA (2026) has not acted against pet-food use. Toxicity is a high-dose phenomenon; natural K1 (phylloquinone) preferred by premium brands. Caution (not avoid): permitted with AAFCO safety recommendation, contested, synthetic.
What It Is
A synthetic, cheaper form of vitamin K.
Menadione is the synthetic vitamin K (K3) the FDA pulled from human supplements over high-dose toxicity - yet it’s still the cheap default in many pet foods. The fuller picture: a 2021 AAFCO expert panel judged it safe at feed levels, and the FDA hasn’t moved against it. The worry is real only at high doses (it stresses red blood cells and the liver). Dogs make their own vitamin K from gut bacteria; cats on fishy diets may need a supplement. Premium brands use natural K1 instead - if you’d rather skip the synthetic, that’s the label to look for.
Evidence & Status
For Dogs & Cats
Dogs
So-so
Cats
So-so
AAFCO / FDA status
Prior-sanctioned vitamin K source; 2021 AAFCO panel recommends MSBC as safe/suitable for all animals (GMP); FDA has not acted against pet-food use (2026).
Applies to
both
Halal Status: Halal
Synthetic; permissible.
Standard: MS 1500:2019; GSO 2055-1; JAKIM e-SMAF
Also Known As
vitamin K3 · MSBC · menadione sodium bisulfite · menadione dimethylpyrimidinol bisulfite
Primary Source
Evidence, not medical advice. You decide.
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