Last update
3/28/2026
Reviewed By
Overview
SCIENTIFIC SCORE
Moderately Effective
Based on 1 Research
8
USERS' SCORE
Moderately Good
Based on 10 Reviews
7.7
Supplement Facts
Serving Size: 2 Capsules
Amount Per Serving
%DV
Vitamin C(as Ester-C® Calcium Ascorbate)
1,000 mg (1 g)
1,111%
Calcium(as Ester-C® Calcium Ascorbate)
110 mg
8%
Citrus Bioflavonoids ComplexCitrus Bioflavonoids (Citrus limon) (fruit), Sweet Orange,Tangerine, Lime, Lemon, Acerola, Rutin, Hesperidin Complex(Citrus spp.) (fruit), Naturally Occurring Vitamin C Metabolites
400 mg
**
Top Medical Research Studies
8
We examined how different vitamin C formulations affect kidney stones, particularly focusing on Ester-C. This well-structured study utilized a randomized, double-blind, crossover design to assess the impact of Ester-C compared to regular ascorbic acid.
We found that Ester-C significantly lowered urine oxalate levels, a key risk factor for kidney stones. This discovery could be a promising step forward, but it also emphasizes the need for further clinical studies to fully understand its effects.
We found that Ester-C significantly lowered urine oxalate levels, a key risk factor for kidney stones. This discovery could be a promising step forward, but it also emphasizes the need for further clinical studies to fully understand its effects.
Read More
Most Useful Reviews
9
Kidney stone protection
This vitamin C with bioflavonoids is superb and doesn't negatively impact kidney health. I've had excellent results, but it's crucial to adhere to the recommended dosage to avoid kidney stones.
Read More
7.5
Improved skin health
21 people found this helpful
I reordered this vitamin C because it's not acidic and does not pose a risk of kidney stones. It's a powerful antioxidant that supports immune function and collagen synthesis. I noticed my skin became fresher and smoother, and I felt more energetic. My husband also took it, and we didn't get ill during the autumn and winter, unlike last year. I recommend staying hydrated with water daily.
Read More
7.5
Effective for illnesses
21 people found this helpful
This vitamin C formula absorbs well, even for those with sensitive stomachs. It contains bioflavonoids which enhance its effectiveness. However, as it contains calcium, those with kidney stones should consider an alternative. Overall, it's a must-have in my antiviral medicine cabinet.
Read More
Medical Researches
SCIENTIFIC SCORE
Moderately Effective
Based on 1 Research
8
- All Researches
8
We examined how different vitamin C formulations affect kidney stones, particularly focusing on Ester-C. This well-structured study utilized a randomized, double-blind, crossover design to assess the impact of Ester-C compared to regular ascorbic acid.
We found that Ester-C significantly lowered urine oxalate levels, a key risk factor for kidney stones. This discovery could be a promising step forward, but it also emphasizes the need for further clinical studies to fully understand its effects.
We found that Ester-C significantly lowered urine oxalate levels, a key risk factor for kidney stones. This discovery could be a promising step forward, but it also emphasizes the need for further clinical studies to fully understand its effects.
Read More
User Reviews
USERS' SCORE
Moderately Good
Based on 10 Reviews
7.7
- All Reviews
- Positive Reviews
- Negative Reviews
9
Kidney stone protection
This vitamin C with bioflavonoids is superb and doesn't negatively impact kidney health. I've had excellent results, but it's crucial to adhere to the recommended dosage to avoid kidney stones.
Read More
7.5
Improved skin health
21 people found this helpful
I reordered this vitamin C because it's not acidic and does not pose a risk of kidney stones. It's a powerful antioxidant that supports immune function and collagen synthesis. I noticed my skin became fresher and smoother, and I felt more energetic. My husband also took it, and we didn't get ill during the autumn and winter, unlike last year. I recommend staying hydrated with water daily.
Read More
7.5
Effective for illnesses
21 people found this helpful
This vitamin C formula absorbs well, even for those with sensitive stomachs. It contains bioflavonoids which enhance its effectiveness. However, as it contains calcium, those with kidney stones should consider an alternative. Overall, it's a must-have in my antiviral medicine cabinet.
Read More
7.5
Safe and effective
8 people found this helpful
I buy buffered vitamin C as a preventative measure against infections. It's gentler on the stomach and poses no risk of kidney stones. This vitamin acts faster, is absorbed better, and lasts longer in the body. I take 0.5 to 1 gram daily and increase the dose if I feel unwell.
Read More
7.5
Effective and safe
7 people found this helpful
I purchase buffered vitamin C for infection prevention. It is a non-acidic form with no risk of kidney stones and works faster than ordinary vitamin C. My daily intake is 0.5 to 1 gram, increasing if I feel ill, which usually does the trick.
Read More
Frequently Asked Questions
7.5
Improved skin health
21 people found this helpful
I reordered this vitamin C because it's not acidic and does not pose a risk of kidney stones. It's a powerful antioxidant that supports immune function and collagen synthesis. I noticed my skin became fresher and smoother, and I felt more energetic. My husband also took it, and we didn't get ill during the autumn and winter, unlike last year. I recommend staying hydrated with water daily.
9
Kidney stone protection
This vitamin C with bioflavonoids is superb and doesn't negatively impact kidney health. I've had excellent results, but it's crucial to adhere to the recommended dosage to avoid kidney stones.
0
Changed composition concern
I stopped using this vitamin C because the calcium may promote kidney stones, and that's not ideal for kidney health.
9
Long-lasting effect
1 people found this helpful
The calcium ascorbate form of vitamin C does not irritate the stomach, and unlike ordinary ascorbic acid, it circulates longer, which is beneficial for preventing kidney stones. The addition of bioflavonoids enhances its effectiveness. I prefer tablets for easy dosage adjustment.
7.5
Safe and effective
8 people found this helpful
I buy buffered vitamin C as a preventative measure against infections. It's gentler on the stomach and poses no risk of kidney stones. This vitamin acts faster, is absorbed better, and lasts longer in the body. I take 0.5 to 1 gram daily and increase the dose if I feel unwell.
7.5
Effective and safe
7 people found this helpful
I purchase buffered vitamin C for infection prevention. It is a non-acidic form with no risk of kidney stones and works faster than ordinary vitamin C. My daily intake is 0.5 to 1 gram, increasing if I feel ill, which usually does the trick.
0
Gentle formulation
2 people found this helpful
I find calcium ascorbate a better option for vitamin C as it's kinder on the stomach and reduces the risk of kidney stones. The Ester-C formula, combined with bioflavonoids, aids absorption. I usually take 500 mg but can increase it during illness as needed.
8
We examined how different vitamin C formulations affect kidney stones, particularly focusing on Ester-C. This well-structured study utilized a randomized, double-blind, crossover design to assess the impact of Ester-C compared to regular ascorbic acid.
We found that Ester-C significantly lowered urine oxalate levels, a key risk factor for kidney stones. This discovery could be a promising step forward, but it also emphasizes the need for further clinical studies to fully understand its effects.
We found that Ester-C significantly lowered urine oxalate levels, a key risk factor for kidney stones. This discovery could be a promising step forward, but it also emphasizes the need for further clinical studies to fully understand its effects.
References
- Moyad MA, Combs MA, Crowley DC, Baisley JE, Sharma P, et al. Vitamin C with metabolites reduce oxalate levels compared to ascorbic acid: a preliminary and novel clinical urologic finding. Urol Nurs. 2009;29:95. PubMed
Data last updated:
