A team of researchers from Spain, Boston (USA), and Bubendorf (Switzerland) has delved into how adipocytes (fat cells) process vitamin D. The recently published findings reveal a key fact: vitamin D3 tends to remain trapped in fatty tissue.
Vitamin D, which we obtain through sun exposure or supplements, does not circulate freely throughout the body. Being a fat-soluble vitamin, it is stored primarily in body fat.
In the study, human adipocytes were cultured and administered both vitamin D3 (its original form) and its active metabolites (25(OH)D3 and 1,25(OH)2D3).
The result was clear: vitamin D3 accumulates in fat and remains there for several days. In contrast, the active forms quickly enter cells but are eliminated within a few hours. Furthermore, when lipolysis (the process of fat breakdown) was stimulated, adipocytes released vitamin D3 to the outside.
This suggests that it is possible to mobilize some of this stored vitamin, but only under certain conditions such as fasting, exercise, or in states of deficiency.
What does this mean for you?
If you’re overweight, a significant portion of the vitamin D you consume may be stored in fat, unavailable for essential functions such as:
- Bone strengthening
- Immune defense
- Regulation of metabolism
For this reason, obese people often need two to three times more vitamin D to achieve optimal blood levels.
The interesting thing about this study is that it is not based solely on clinical observations, but on direct evidence at the human cellular level.
In short: Your fat tissue may be “storing” vitamin D, but this isn’t always beneficial if your body can’t use it when it needs it.
This discovery opens up new possibilities for improving supplementation strategies for people who are overweight or obese.
Link: https://www.mdpi.com/2072-6643/17/13/2107
Date: 06/25/2025
Source: MDPI
Photography: Pixabay
Note: The Nutrigenomics Institute is not responsible for the opinions expressed in this article.
