Vitamin D Blood Test with Doctor-Written Report
Find out whether your vitamin D is low, sufficient or too high — checked at a UKAS-accredited UK lab and explained by Dr James Coleman, with a clear next step. Home finger-prick or venous sample.
A vitamin D test is only useful if you understand what to do with the result. For £49 you don't just get a number — you get a GP-written explanation of what it means and what to do next.
See how we turn your result into a clear plan
Most vitamin D tests just give you a number. This is where Brooksby is different: a named doctor reviews your result alongside the short health questionnaire you complete, then explains what it means for you and what to do next.
Read a full example report →
Your vitamin D level is 32 nmol/L. This is a little low. In most people, we would usually like this to be above 50 nmol/L, so it is worth improving.
You told us you have been feeling tired. Low vitamin D can sometimes contribute to tiredness, muscle aches or feeling generally run down, but it is rarely the only possible cause. That is why your result is reviewed alongside the information you give us about your symptoms, diet, lifestyle and risk factors, rather than treated as just a number.
A sensible next step would usually be vitamin D3 1,000–2,000 IU once daily. This is especially important during autumn and winter, when UK sunlight is usually not strong enough for most people to make enough vitamin D through the skin. Some people may need to continue this longer term, especially if they spend most of their time indoors, cover most of their skin outdoors, have darker skin, follow a restricted diet, have had low vitamin D before, or have gut conditions that affect absorption.
Lifestyle can help too. From late March to the end of September, regular safe time outdoors can help your body make vitamin D. Food sources include oily fish, eggs, red meat, liver and fortified foods, although diet alone is often not enough to correct a low level.
My advice would be to take vitamin D3 consistently and see whether your tiredness improves. A repeat test after a few months can confirm that your level has corrected. If you still feel tired despite improving your vitamin D, your included doctor call can help decide whether we should look for other causes, such as low iron, B12, folate, thyroid problems, sleep issues or mood.
Summary: your vitamin D is mildly low. Daily vitamin D3 is a reasonable next step, and your report turns the result into a practical plan based on your symptoms and risk factors.
Worth testing if any of these apply
With limited sunlight for much of the UK year, low vitamin D is common — and it can quietly affect your energy, muscles and bone health.
Low, sufficient, or too high
Low
Below 50 nmol/L. You may benefit from supplementation or a look at your risk factors. Your report explains the right next step for you.
Sufficient
Above 50 nmol/L is generally sufficient for most people. You may simply continue sensible maintenance advice — we'll confirm what fits you.
Too high
Important if you take high-dose supplements. Too much vitamin D can raise blood calcium and, over time, affect the kidneys, bones and heart — so a high result matters as much as a low one.
There is no single agreed “optimal” level. Your Brooksby report interprets your number against your symptoms, risk factors and any supplements you take — not a fixed cut-off.
Most tests give you a number. Brooksby gives you a clear next step.
Many home blood tests stop at the result. Brooksby goes further: the number, what it means, and what to do next — explained by a named GP.
Written by a named GP
Your report is written and signed by Dr Coleman — not auto-generated, not outsourced.
Doctor call if you want it
A one-to-one call with Dr Coleman to talk your result through — included at no extra cost, and there only if you want it.
UKAS-accredited UK lab
The same accreditation standard used by NHS hospitals. Consistent, reliable analysis.
No subscription
One-off purchase. You order the test, you get the report, you own the data.
Dr James Coleman
“A vitamin D number on its own rarely helps. I read your result in the context of your symptoms and risk factors, and tell you plainly what — if anything — to do about it.”
Simple from start to finish
Order your test
Choose online in minutes. Your kit is dispatched in a plain box.
Collect your sample
Finger-prick at home in under five minutes, or arrange a venous draw — whichever suits.
Post it back
Drop your pre-paid, tracked envelope in any postbox. We take it from there.
Your doctor-written report
Reviewed by Dr Coleman and delivered to your secure portal within 2–3 working days.
Doctor call (optional)
If you'd like, a link to book a private call with Dr Coleman to talk your result through. Included, entirely up to you.
You're never left wondering where your sample is.
From the moment your kit is dispatched to the second your report is ready, we send you a short SMS at every stage. No app to download. No inbox digging. Just clear, timely confirmation that everything is moving as it should.
Choose how you'd like your sample taken
Pick the option that suits you. The test is the same. Only the way we collect your sample changes.
- Doctor-reviewed report
- Free tracked delivery
- Results in 2–3 working days
- Actionable next steps
Common questions
Everything you need to know before ordering your vitamin D test.
What does a vitamin D blood test measure?
This test measures the level of 25-hydroxyvitamin D in your blood, which is the main circulating form of vitamin D. It reflects your overall vitamin D status from both sunlight exposure and dietary intake, and is the standard marker used by doctors to assess bone, muscle and calcium health.
Who should consider a vitamin D test?
Vitamin D testing is particularly useful for:
People who spend limited time outdoors or live in the UK
Those with darker skin tones
Anyone experiencing fatigue, bone pain, or muscle weakness
People supplementing vitamin D who want to check levels
Those with conditions affecting absorption (e.g. coeliac, Crohn's)
What is a normal vitamin D level in the UK?
In UK clinical practice, vitamin D (measured in nmol/L) is usually interpreted as:
Below 25 nmol/L — deficient
25–50 nmol/L — insufficient
Above 50 nmol/L — generally sufficient for most people
There is no universally agreed "optimal" level, and some laboratories or specialists discuss higher target ranges depending on context. Rather than reading your number against a fixed cut-off, your Brooksby report interprets it in relation to your symptoms, risk factors and any supplements you take — and sets out what, if anything, to do next.
Should I get tested, or just take a supplement?
Not everyone needs a vitamin D blood test. Many people can simply follow NHS advice and take a standard daily vitamin D supplement (10 micrograms) during the autumn and winter months.
Testing is more useful if you have symptoms, known risk factors, previous deficiency, a condition affecting absorption, bone pain or muscle weakness, darker skin, limited sun exposure — or if you are already supplementing and want to check whether your level is now in range, or has climbed too high. If you are unsure whether testing is right for you, you are welcome to ask us before ordering.
Can vitamin D be too high?
Yes. Vitamin D is fat-soluble, so it can build up if you take high-dose supplements over time. Too much can raise blood calcium (hypercalcaemia), which over time can affect the kidneys, bones and heart. The NHS advises most adults not to take more than 100 micrograms (4,000 IU) a day unless a doctor has advised otherwise.
This is why testing isn't only about checking for a low level — if you supplement, it is also a way to confirm you are not drifting too high. Your GP-written report will flag this clearly and explain what to do.
Do I need to fast for a vitamin D test?
No fasting is required. You can eat and drink normally before this test. Stay well hydrated for an easier blood draw.
How will I receive my vitamin D results?
Secure online results with a GP-written explanation from Brooksby Medical in 2–3 working days.
Ask us before you order.
Not everyone needs a vitamin D blood test. If you're unsure whether it's right for you, drop us a message — a real person replies, usually within one working day.
Ready to understand your vitamin D properly?
Order your home vitamin D blood test and get a GP-written explanation with clear next steps — from a UKAS-accredited UK lab, with a one-to-one call with Dr Coleman if you want to talk it through.
Order your test — £49