Journal
Plain-English science on vitamin D, deficiency, testing methods, and what your number actually means.
MetabolismVitamin D and weight: the obesity connection you should know about
People with higher body weight are consistently more likely to be vitamin D deficient — and often need higher doses to correct it. Here's the biology,...
Read more
How it worksWhat is VMR? The Vitamin D Metabolite Ratio explained
Your 25(OH)D level tells you how much vitamin D is in your blood. The Vitamin D Metabolite Ratio tells you whether your body is actually using...
Read more
ImmunityVitamin D and immunity: what the research actually shows
Every immune cell carries a vitamin D receptor — which is why low levels are linked to more frequent respiratory infections. Here's what the evidence actually...
Read more
ComparePharmacy rapid vitamin D tests vs lab-based testing: what's the difference?
Pharmacy rapid tests are cheap and quick — but they're not measuring vitamin D the same way a lab does. Here's what the difference actually means...
Read moreStop guessing.Start knowing.
The whole process takes less time than booking a GP appointment — and tells you more about your vitamin D than a standard blood test.