Vitamin D gets trapped in fat cells - improved understanding - Holick Jan 2025

---

Interaction of Vitamin D-BODIPY With Fat Cells and the Link to Obesity-associated Vitamin D Deficiency

Anticancer Research January 2025, 45 (1) 55-63; DOI: https://doi.org/10.21873/anticanres.17392
NAZLI UÇAR, JUDE T. DEENEY, R. TAYLOR PICKERING, TING-YU FAN, RALF LOO, PETER M. MUELLER and MICHAEL F. HOLICK

Background/Aim: Obese individuals often exhibit vitamin D deficiency, potentially due to sequestration in fat cells. Little is known about how vitamin D3 enters adipocytes and associates with the intracellular lipid droplet.

Materials and Methods: Newly differentiated human and mouse (3T3-L1) adipocytes and primary mouse adipocytes were treated with vitamin D3 covalently linked to green fluorescent BODIPY (VitD-B) or Green BODIPY (GB) as control. Cells were exposed to 10-100 nM concentrations for various lengths of time (1-48 h). Fluorescence microscopy assessed vitamin D distribution.

Results: VitD-B demonstrated stable incorporation into adipocytes without enzymatic cleavage, as HPLC showed no free vitamin D3 after 72 h. Fluorescence microscopy showed GB uptake was rapid and persisted for 48 h. VitD-B uptake was more gradual compared to GB in the human and 3T3-L1 adipocytes. Primary mouse adipocytes exhibited similar uptake patterns, with VitD-B appearing within 1 h and fluorescence intensity increasing 1.2-fold at 8 h and 5.7-fold at 24 h. GB exhibited rapid fluorescence uptake in these same cells, 29-fold higher than VitD-B at 1 h. At 24 h, some VitD-B treated cells exhibited greater fluorescence intensity around the surface of the lipid droplets, which was not observed in GB. Isolated lipid droplets exhibited rapid and immediate uptake of both VitD-B and GB, indicating a strong affinity for these lipid structures. The time-dependent accumulation of vitamin D3 in human adipocytes mirrored VitD-B uptake.

Conclusion: VitD-B is a reliable proxy for studying the dynamics of vitamin D3 uptake in adipocytes.
 Download the PDF from VitaminDWiki

---

Main points of the study by Perplexity AI - Jan 2024

This research paper investigates how vitamin D interacts with fat cells (adipocytes), with key findings organized as follows:
Methodology and Tools

• Researchers developed a fluorescent-labeled vitamin D (VitD-B) to track its movement in fat cells
• The study examined both human and mouse fat cells, including cultured cells and primary cells extracted from tissue
• VitD-B proved stable over 72 hours with no breakdown, making it a reliable research tool

Key Findings
Uptake Patterns

• VitD-B enters fat cells gradually over time, unlike the control substance (GB) which enters quickly
• After 24 hours, some cells showed a distinctive "halo" pattern of vitamin D around their lipid droplets
• The time-dependent accumulation of regular vitamin D matched the pattern seen with VitD-B

Cell Type Comparisons

• Similar uptake patterns were observed across different cell types:
  • Human fat cells
  • Mouse 3T3-L1 cells
  • Primary mouse fat cells

Clinical Implications
Obesity Connection

• The research helps explain why obese individuals often have vitamin D deficiency
• As fat tissue increases, more vitamin D becomes trapped in fat cells
• This sequestration reduces vitamin D's availability to the rest of the body

Research Limitations

• The study was limited to 48 hours, preventing understanding of long-term effects
• In vitro models may not fully replicate the complexity of living tissue
• The isolation process for lipid droplets may have disrupted some cellular mechanisms

---

VitaminDWiki – Overview Obesity and Vitamin D contains:

• FACT: People who are obese have less vitamin D in their blood
• FACT: Obese need a higher dose of vitamin D to get to the same level of vit D
• FACT: When obese people lose weight the vitamin D level in their blood increases
• FACT: Adding Calcium, perhaps in the form of fortified milk, often reduces weight
• FACT: 168 trials for vitamin D intervention of obesity as of Dec 2021
• FACT: Less weight gain by senior women with > 30 ng of vitamin D
• FACT: Dieters lost additional 5 lbs if vitamin D supplementation got them above 32 ng - RCT
• FACT: Obese lost 3X more weight by adding $10 of Vitamin D
• FACT: Those with darker skins were more likely to be obese Sept 2014
• OBSERVATION: Low Vitamin D while pregnancy ==> more obese child and adult
• OBSERVATION: Many mammals had evolved to add fat and vitamin D in the autumn
  • and lose both in the Spring - unfortunately humans have forgotten to lose the fat in the Spring
• SPECULATION: Low vitamin D might be one of the causes of obesity – several studies
• SUGGESTION: Probably need more than 4,000 IU to lose weight if very low on vitamin D due to
    risk factors such as overweight, age, dark skin, live far from equator,shut-in, etc.
• Obesity category has 443 items

See also: Weight loss and Vitamin D - many studies   Child Obesity and Vitamin D - many studies   Obesity, Virus, and Vitamin D - many studies
Obese need more Vitamin D

• Normal weight     Obese     (50 ng = 125 nanomole)

Click here for 2014 study

Obesity category is associated with Diabetes 35, Intervention 33, Infant-Child 30, Youth 24, Metabolic Syndrome 21, Skin - Dark 20, Virus 19, Women 16, VDR 16, Pregnancy 15, etc.

Calcium 15, Genetics 15, Omega-3 13, Magnesium 11, Intervention - non daily 10, Liver 9, How much Vitamin D 9, Cardiovascular 9, Antibiotics, probiotics 8, Cancer 7, Deficiency 7, Sports 7, Seniors 7, Hypertension 6, Loading dose 4, Vit D Binding Protein 4, Breathing 4, Bone - Health 4, Gut 4, Multiple Sclerosis 4, Predict Vitamin D 4, UV 4

---

57+ VitaminDWiki pages have HOLICK in the title

The list is automatically updated