What we measure
This test measures the level of vitamin D in your blood. Vitamin D is an important nutrient that contributes to bone, skin, and muscle health, but also influences our immunity, mood, and more. In the UK, we get around 80-90% of our vitamin D from sunlight exposure, while 10-20% comes from our diet. Around one in five adults may have low levels of vitamin D.
This test can help indicate whether you’re deficient in vitamin D.
Because we mostly get vitamin D from sunlight, between the months of October-March most people in the UK will need to top up their levels in another way.
It can be difficult to get enough vitamin D from your diet alone because not that many foods contain it. These include oily fish, red meat, and egg yolks.
For adults in the UK, the recommended amount of vitamin D is 10 micrograms per day. To put this in context, 100g of chicken breast contains around 1% of your daily recommended amount. So, per UK health guidelines, adults should take a daily vitamin D supplement in the autumn and winter.
Anyone can take a vitamin D test, but it may be more suitable for people experiencing symptoms of vitamin D deficiency or who want to check whether vitamin D replacement therapy has been successful.
You may be more at risk of vitamin D deficiency if you’re aged 65 years or over, have no or low exposure to the sun, have darker skin pigmentation, have severe liver or kidney disease, are pregnant or breastfeeding, or are overweight.
what to expect
Your results will tell you how much vitamin D is present in your blood and whether this is within a normal (healthy), insufficient, or deficient range. You’ll also get some recommendations that explain how you can act on this information.
On blood test results, vitamin D is measured in units that describe how much of it is present in the blood, such as nanomoles (nmol) per litre (L). What’s most important is which range this number falls into.
If left untreated, low vitamin D levels can eventually cause health problems, such as thinning of the bones (osteoporosis). This can be corrected by taking supplements. If your levels are very low, your doctor might prescribe high-strength vitamin D supplements for a short while to boost them back up.
Need help? Speak with an expert
Don’t quite understand your results or simply want to see a doctor? We’ve got you sorted.
Speak to a GP
Book an online consultation with one of our GPs. We offer consultations in both English and Chinese.
Just fill out an online form and find a time that’s convenient.
Get a private prescription
Need to get your medication? Our GPs can write private prescriptions.
Tell the GP what the problem is during your consultation and they’ll take it from there. Prescriptions can be picked up at your local pharmacy.
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Signs of a vitamin D deficiency include:
- Chronic exhaustion and feeling tired all the time
- Hair loss
- Muscle pain
- Bone and lower back pain
- Getting sick often (recurrent infections)
No, you don’t need to stop taking it. It’s generally advised that you continue taking your regular supplements, aside from biotin (see the below question), leading up to your test. If you’re taking any prescribed or high-dose supplements, just let your provider know before they do the test.
If you’re taking a supplement called biotin, which is a type of vitamin B that’s usually found in supplements promoting nail, skin, and hair health, it’s recommended that you don’t take it for at least 48 hours before the test. This is because it can interfere with your results.
If you’ve been prescribed biotin by a doctor, then it’s important you check with them before stopping or pausing your dose.
Aside from that, there’s nothing else you need to do.
Yes, you can. A vitamin D blood test does not require you to fast (not eat or drink anything except water) ahead of the test.
Test results are available in 2 working days. Simply log into our website to retrieve them.
Yes, our vitamin D blood tests are safe and accurate. Blood tests are the only way to know for sure if you’re deficient in vitamin D.
We work with top labs and all our test results are validated by HCPC scientists and GMC doctors. Plus, we’re regulated by the CQC, which is a quality mark for health services you can trust, and are UKAS accredited. You can find us listed on the UK government website.
Our vitamin D blood test is quick and easy. If you’re using the finger-prick method, simply follow the instructions in the kit. The test itself shouldn’t take longer than a few minutes. When you have your sample, simply post it to our lab using the free envelope provided.
If you’re have a blood test done (phlebotomy) at your local pharmacy, you’ll just need to sit in a chair while their phlebotomist draws blood from your arm. The test will be over in a matter of minutes. You don’t need to worry about posting anything—our courier will pick up the test.
You’ll receive results in 2 working days.