Educational information from Her Form — reviewed for accuracy by our health specialists.
Not a substitute for personal medical advice. Optional 1:1 consults with Robyn, our consulting women's-health specialist, are available on request.
What it is
B12 is found almost exclusively in animal foods. Vegetarian and vegan women, and anyone on long-term acid blockers or metformin, are at high risk of deficiency.
Why it matters for women
Low B12 mimics hypothyroidism and depression — fatigue, brain fog, low mood, tingling, palpitations.
Optimal range
>500 pg/mL (or active B12 >70 pmol/L).
Standard lab range
Lab cut-off is 200 — neurological symptoms appear well above that.
When it's high
- ↑Usually benign — supplementation, or rarely liver/kidney issues
When it's low
- ↓Fatigue, brain fog
- ↓Tingling hands/feet
- ↓Low mood
- ↓Palpitations
References
- Endocrine Society — Female hormone health— Sex hormone assessment and interpretation in women
- Jean Hailes for Women's Health— Comprehensive women's hormone health guidance
- RANZCOG — Women's health guidelines— ANZ clinical standards for reproductive-age women
- NICE — Women's health guidelines— Evidence-based hormone and reproductive health guidance
References are provided for educational context only. Always interpret results with a qualified healthcare professional.
A note on interpretation. Ranges above are what our health specialists works to in healthy women. They are not a diagnosis — a single result always needs context from your symptoms, cycle phase and other markers.