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
Vitamin D is technically a hormone, synthesised in skin from sunlight and converted by liver and kidneys. Despite living near the equator, deficiency is common in Bali expats (indoor work, sunscreen, modest dress).
Why it matters for women
Adequate vitamin D supports fertility, bone density through perimenopause, immune function and mood.
Optimal range
50–80 ng/mL.
Standard lab range
Lab cut-off for deficiency is <20 — well below optimal.
When it's high
- ↑Usually only from supplementation >10,000 IU/day
When it's low
- ↓Fatigue, low mood
- ↓Frequent infections
- ↓Bone or muscle aches
- ↓Hair shedding
References
- Endocrine Society — Vitamin D deficiency guidelines— Optimal vitamin D levels, testing and supplementation
- RACGP — Vitamin D in adults— Vitamin D screening, deficiency thresholds and treatment
- NICE — Vitamin D supplementation— Evidence-based vitamin D guidance for at-risk groups
- Jean Hailes — Bone health and vitamin D— Vitamin D role in perimenopause bone protection
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.