Last update
5/10/2026
Reviewed By
Overview
SCIENTIFIC SCORE
Moderately Effective
Based on 2 Researches
8
USERS' SCORE
Good
Based on 4 Reviews
8.2
Supplement Facts
Serving Size: 1 Vegetarian Tablet
Amount Per Serving
%DV
Vitamin C (as Ester-C® Calcium Ascorbate)
1,000 mg (1 g)
1,111%
Calcium (as Ester-C® Calcium Ascorbate)
108 mg
8%
Citrus Bioflavonoids ComplexCitrus Bioflavonoids (Citrus spp.) (fruit), Sweet Orange, Tangerine, Lime, Lemon, Acerola, Rutin, Hesperidin Complex (Citrus spp.) (fruit), Naturally Occurring Vitamin C Metabolites
200 mg
**
Top Medical Research Studies
9
We delved into how vitamin C might influence cancer treatment, focusing on its effects on the immune system. Our findings revealed that vitamin C directly modifies certain proteins, leading to a new type of protein change called vitcylation. This process specifically affects a protein known as STAT1.
By modifying STAT1, vitamin C enhances its ability to signal for immune responses. We found that this modification occurs in both controlled environments and living cells, depending on factors like dosage and acidity. As a result of vitcylation, the action of STAT1 is improved, which activates important immune responses in tumor cells and boosts the expression of molecules that help the immune system recognize and attack cancer cells.
Interestingly, this research sheds light on the potential of vitamin C as a treatment that not only affects cancer directly but also empowers the body’s own defenses. These insights pave the way for new approaches to cancer therapy that leverage the immune system in conjunction with vitamin C.
By modifying STAT1, vitamin C enhances its ability to signal for immune responses. We found that this modification occurs in both controlled environments and living cells, depending on factors like dosage and acidity. As a result of vitcylation, the action of STAT1 is improved, which activates important immune responses in tumor cells and boosts the expression of molecules that help the immune system recognize and attack cancer cells.
Interestingly, this research sheds light on the potential of vitamin C as a treatment that not only affects cancer directly but also empowers the body’s own defenses. These insights pave the way for new approaches to cancer therapy that leverage the immune system in conjunction with vitamin C.
Read More
7
Novel nanoparticle system demonstrates enhanced cancer-fighting potential
We designed a specialized nanoparticle system combining copper-doped metal-organic frameworks with calcium ascorbate (a form of vitamin C) to fight cancer more effectively. The system is wrapped in hyaluronic acid, which acts like a homing beacon to target tumors.
Once inside tumor cells, the nanoparticles release calcium ascorbate, which generates hydrogen peroxide—a powerful cancer-fighting molecule. At the same time, the released copper works to strip away glutathione, a natural defense that cancer cells use to protect themselves. This one-two punch creates toxic hydroxyl radicals that damage cancer cells while reducing their ability to survive.
Our tests showed this approach significantly enhanced cancer cell death compared to traditional methods, suggesting a promising new strategy for more effective chemodynamic therapy.
Once inside tumor cells, the nanoparticles release calcium ascorbate, which generates hydrogen peroxide—a powerful cancer-fighting molecule. At the same time, the released copper works to strip away glutathione, a natural defense that cancer cells use to protect themselves. This one-two punch creates toxic hydroxyl radicals that damage cancer cells while reducing their ability to survive.
Our tests showed this approach significantly enhanced cancer cell death compared to traditional methods, suggesting a promising new strategy for more effective chemodynamic therapy.
Read More
Most Useful Reviews
9
Vital for immune system
It works! I find this Ester-C absorbs more readily and significantly supports my immune system after cancer. I make sure to keep it stocked at home to combat colds, and I can increase the dosage without upsetting my stomach.
Read More
7.5
Survivor support
5 people found this helpful
I highly recommend Ester-C as it is buffered, making it easy to take without stomach upset. As a grade IV GBM brain cancer survivor for 18 years, I have taken up to 14 grams a day but currently take 7 in divided doses. It has been a mainstay in my supplement regimen, greatly supporting my overall health.
Read More
7.5
Anti-cancer programme
I’m taking 8 grams a day as part of an anti-cancer programme suggested by my doctor.
Read More
Medical Researches
SCIENTIFIC SCORE
Moderately Effective
Based on 2 Researches
8
- All Researches
9
We delved into how vitamin C might influence cancer treatment, focusing on its effects on the immune system. Our findings revealed that vitamin C directly modifies certain proteins, leading to a new type of protein change called vitcylation. This process specifically affects a protein known as STAT1.
By modifying STAT1, vitamin C enhances its ability to signal for immune responses. We found that this modification occurs in both controlled environments and living cells, depending on factors like dosage and acidity. As a result of vitcylation, the action of STAT1 is improved, which activates important immune responses in tumor cells and boosts the expression of molecules that help the immune system recognize and attack cancer cells.
Interestingly, this research sheds light on the potential of vitamin C as a treatment that not only affects cancer directly but also empowers the body’s own defenses. These insights pave the way for new approaches to cancer therapy that leverage the immune system in conjunction with vitamin C.
By modifying STAT1, vitamin C enhances its ability to signal for immune responses. We found that this modification occurs in both controlled environments and living cells, depending on factors like dosage and acidity. As a result of vitcylation, the action of STAT1 is improved, which activates important immune responses in tumor cells and boosts the expression of molecules that help the immune system recognize and attack cancer cells.
Interestingly, this research sheds light on the potential of vitamin C as a treatment that not only affects cancer directly but also empowers the body’s own defenses. These insights pave the way for new approaches to cancer therapy that leverage the immune system in conjunction with vitamin C.
Read More
7
Novel nanoparticle system demonstrates enhanced cancer-fighting potential
We designed a specialized nanoparticle system combining copper-doped metal-organic frameworks with calcium ascorbate (a form of vitamin C) to fight cancer more effectively. The system is wrapped in hyaluronic acid, which acts like a homing beacon to target tumors.
Once inside tumor cells, the nanoparticles release calcium ascorbate, which generates hydrogen peroxide—a powerful cancer-fighting molecule. At the same time, the released copper works to strip away glutathione, a natural defense that cancer cells use to protect themselves. This one-two punch creates toxic hydroxyl radicals that damage cancer cells while reducing their ability to survive.
Our tests showed this approach significantly enhanced cancer cell death compared to traditional methods, suggesting a promising new strategy for more effective chemodynamic therapy.
Once inside tumor cells, the nanoparticles release calcium ascorbate, which generates hydrogen peroxide—a powerful cancer-fighting molecule. At the same time, the released copper works to strip away glutathione, a natural defense that cancer cells use to protect themselves. This one-two punch creates toxic hydroxyl radicals that damage cancer cells while reducing their ability to survive.
Our tests showed this approach significantly enhanced cancer cell death compared to traditional methods, suggesting a promising new strategy for more effective chemodynamic therapy.
Read More
User Reviews
USERS' SCORE
Good
Based on 4 Reviews
8.2
- All Reviews
- Positive Reviews
- Negative Reviews
9
Vital for immune system
It works! I find this Ester-C absorbs more readily and significantly supports my immune system after cancer. I make sure to keep it stocked at home to combat colds, and I can increase the dosage without upsetting my stomach.
Read More
7.5
Survivor support
5 people found this helpful
I highly recommend Ester-C as it is buffered, making it easy to take without stomach upset. As a grade IV GBM brain cancer survivor for 18 years, I have taken up to 14 grams a day but currently take 7 in divided doses. It has been a mainstay in my supplement regimen, greatly supporting my overall health.
Read More
7.5
Anti-cancer programme
I’m taking 8 grams a day as part of an anti-cancer programme suggested by my doctor.
Read More
6
Supports recovery
Ester-C with Citrus Flavonoids is an excellent product that fills the gaps with other Vitamin C sources. I take 2 grams daily for recovery after cancer, especially when my food isn't organic. Alternate between different Vitamin C types for best results.
Read More
Frequently Asked Questions
7.5
Anti-cancer programme
I’m taking 8 grams a day as part of an anti-cancer programme suggested by my doctor.
9
Vital for immune system
It works! I find this Ester-C absorbs more readily and significantly supports my immune system after cancer. I make sure to keep it stocked at home to combat colds, and I can increase the dosage without upsetting my stomach.
6
Supports recovery
Ester-C with Citrus Flavonoids is an excellent product that fills the gaps with other Vitamin C sources. I take 2 grams daily for recovery after cancer, especially when my food isn't organic. Alternate between different Vitamin C types for best results.
9
We delved into how vitamin C might influence cancer treatment, focusing on its effects on the immune system. Our findings revealed that vitamin C directly modifies certain proteins, leading to a new type of protein change called vitcylation. This process specifically affects a protein known as STAT1.
By modifying STAT1, vitamin C enhances its ability to signal for immune responses. We found that this modification occurs in both controlled environments and living cells, depending on factors like dosage and acidity. As a result of vitcylation, the action of STAT1 is improved, which activates important immune responses in tumor cells and boosts the expression of molecules that help the immune system recognize and attack cancer cells.
Interestingly, this research sheds light on the potential of vitamin C as a treatment that not only affects cancer directly but also empowers the body’s own defenses. These insights pave the way for new approaches to cancer therapy that leverage the immune system in conjunction with vitamin C.
By modifying STAT1, vitamin C enhances its ability to signal for immune responses. We found that this modification occurs in both controlled environments and living cells, depending on factors like dosage and acidity. As a result of vitcylation, the action of STAT1 is improved, which activates important immune responses in tumor cells and boosts the expression of molecules that help the immune system recognize and attack cancer cells.
Interestingly, this research sheds light on the potential of vitamin C as a treatment that not only affects cancer directly but also empowers the body’s own defenses. These insights pave the way for new approaches to cancer therapy that leverage the immune system in conjunction with vitamin C.
References
- Zhang M, Xue H, Yang J, Zhao X, Xue M, et al. Copper(II)-based metal-organic framework delivery of calcium ascorbate for enhanced chemodynamic therapy HO self-supply and glutathione depletion. Biomater Sci. 2024;12:1871. 10.1039/d3bm01922e
- He X, Wang Q, Cheng X, Wang W, Li Y, et al. Lysine vitcylation is a vitamin C-derived protein modification that enhances STAT1-mediated immune response. Cell. 2025. 10.1016/j.cell.2025.01.043
