Vitamins & minerals, explained
Vitamin D, B12, folate, magnesium, zinc and more. We tell you what is truly low — and what is just below an optimistic “optimal”.
Three things we do that a printed range doesn’t
Ranges change with both. We use the set for you — 26 range sets in total.
Values change each other’s meaning. We show the links, not just the list.
EFSA NDA, NICE, NORIP (Nordic Reference Interval Project), EFSA. Organisation, document, year.
Vitamin D (25-OH) — the ranges we use
Endocrine Society/ESCEO: deficiency is common and affects bones and immunity.
| Rating | Range | What it means |
|---|---|---|
| Talk to a doctor | below 30 nmol/L | Deficiency (<30 nmol/L) — supplementation is warranted. |
| Worth improving | 30 – 50 nmol/L | Insufficiency (30–50) — maintain your stores (sun/D3 in winter). |
| Good | 50 nmol/L and above | Adequate (≥50, WHO/IOM consensus). ES 2011 proposed ≥75 (withdrawn 2024 — under debate). |
Articles in this guide
- Supplements for better blood: what really worksSupplements & longevity
- Blood tests before pregnancy: what to check before you conceiveLife stages
- Alkaline phosphatase (ALP): what high or low levels meanMarker explained
- Blood test reference values — table by test for adultsReading your report
- Fatigue: which blood tests explain it — and which don'tSymptom → test
- Hashimoto's: what it is, what is proven to help and what the latest research saysMarker explained
- High homocysteine: what it means and how to lower itMarker explained
- High RDW: what red cell distribution width means on your blood testComplete blood count (CBC)
This content is for information only and is not a substitute for medical advice. Talk to your doctor about your results.
Good to know
Vitamin D 41 — do I need a supplement?
Upload your report and you’ll see the answer for your exact value, age and sex — with the source of the range. In general: one value outside the printed range is rarely an emergency; the pattern and the trend matter more.
Do I need a new test?
No. Upload the one you already have. If a re-test is useful, the plan tells you when.
Is this a diagnosis?
No. It is an explanation to help you and your doctor. When a value needs a doctor, we say so.