Taking vitamin D is one thing, which form you take is another.
D3 (cholecalciferol), which you get from sunlight and food, is not used by the body directly. It is first converted in the liver by the enzyme 25-hydroxylase into 25(OH)D, that is, calcidiol (calcifediol). This is exactly the molecule measured as your "vitamin D level" in blood tests. The kidney then converts it into the active form, 1,25(OH)₂D. On this pathway, calcidiol is the form in which the liver conversion step is already complete. Uth-FastD™ offers calcidiol in a small, easy-to-swallow tablet made with VitamoreD™ technology. Calcidiol is not a new molecule. It is the same intermediate form that your body makes itself. That is why we describe Uth-FastD™ without big adjectives, as "the form that joins the path at a later point".
Why does a blood test look at 25(OH)D?
D3 stays in the blood for a short time and does not show your vitamin D status on its own. 25(OH)D stays in the blood for a long time and reflects the body's vitamin D status. That is why the test looks at this value. The active form, 1,25(OH)₂D, is tightly regulated by calcium and parathyroid hormone and is not measured routinely.[3]
More than half of measurements below 20 ng/mL
A study of 25(OH)D measurements from 706,434 adults in 33 hospitals across 21 provinces of Türkiye found that 57.8% of measurements were below 20 ng/mL and 21.9% were in the 20–30 ng/mL range.[4] It is a hospital-based sample and does not represent the general population. A blood test is the way to find out your own level. We explain how to convert a result between ng/mL and nmol/L in the vitamin D guide.
Authorised health claims for vitamin D*
- Vitamin D contributes to normal absorption/utilisation of calcium and phosphorus.*
- Vitamin D contributes to normal blood calcium levels.*
- Vitamin D contributes to the maintenance of normal bones.*
- Vitamin D contributes to the maintenance of normal muscle function.*
- Vitamin D contributes to the maintenance of normal teeth.*
- Vitamin D contributes to the normal function of the immune system.*
- Vitamin D has a role in the process of cell division.*
Source: EFSA NDA Panel[1] and the Turkish Food Codex Regulation on Nutrition and Health Claims[2]. The claims belong to the nutrient (vitamin D), not to the product.
A small tablet, a form further along the path
VitamoreD™ is a vitamin D technology developed in the United Kingdom. The calcidiol in Uth-FastD™ comes from a yeast-based raw material that is enriched by exposure to sunlight (UV). The tablets weigh 200 mg and are made in the United Kingdom, and every batch is tested by an independent laboratory. They come in packs of 30 and 60 tablets.
Uth-FastD™ is a food supplement, not a medicine. A blood test is the most reliable way to find out your vitamin D level. We suggest you decide on a supplement based on your test result and your physician's view.
Meet Uth-FastD™
