SISU Ester-C Supreme 600mg Buffered Vitamin C Capsules, Calcium Ascorbate with Quercetin
SISU Ester-C Supreme 600mg Details
SISU Ester-C Supreme is buffered, non-acidic vitamin C built around the patented Ester-C® form (calcium ascorbate with naturally occurring vitamin C metabolites), plus added citrus bioflavonoids and quercetin. 600mg per capsule, designed to stay in white blood cells longer than standard ascorbic acid and to be gentler on the stomach. A sensible step up for adults who want a premium-tier vitamin C without going to liposomal liquid territory.
Vitamins Lowest Prices | Lowest Price in Canada — Guaranteed | Ships from Ontario across Canada
Quick Facts
| Brand | SISU |
| Form | Vegetarian capsule |
| Vitamin C | 600mg per capsule (Ester-C® calcium ascorbate) |
| pH | Non-acidic, buffered |
| Added cofactors | Citrus bioflavonoids + quercetin |
| Dose | 1 capsule daily (typical) |
| Diet | Vegetarian, gluten-free |
Who SISU Ester-C Supreme Is For
- You want a buffered, non-acidic vitamin C that's easier on the stomach
- You've tried regular ascorbic acid and found it caused heartburn or stomach upset
- You want vitamin C with cofactors (bioflavonoids, quercetin) like it occurs in nature, not isolated alone
- You want a once-daily dose that's reasonable, not megadose territory
- You want a recognized branded form (Ester-C®) backed by formulation research
- You want a capsule format — no powders, no liquids, no mixing
Who this product is NOT for: Anyone on a strict sodium-restricted or calcium-restricted diet should mention this to their practitioner — Ester-C is calcium ascorbate, so each serving contributes some calcium. Anyone with a history of kidney stones should consult their practitioner before higher-dose vitamin C use. If you want a true liquid liposomal C (Quicksilver or similar) for maximum absorption, that's a different category at a premium-tier price.
Vitamart's Take
Ester-C is a well-known buffered vitamin C — calcium ascorbate with the natural metabolites the body makes when it uses ascorbic acid. The selling point is gentler-on-the-stomach and longer cellular retention than straight ascorbic acid. Added bioflavonoids and quercetin make sense too — in nature, vitamin C never shows up isolated. Sensible everyday C for adults who want more than basic ascorbic acid tablets without going to liposomal liquid pricing.
How SISU Ester-C Supreme Compares
Ester-C Supreme vs Plain Ascorbic Acid
Plain ascorbic acid tablets are the lowest-cost route to vitamin C — fine if your stomach handles them and you don't need cofactors. Ester-C Supreme uses buffered calcium ascorbate (non-acidic) plus added bioflavonoids and quercetin. Choose plain ascorbic acid for budget daily use; choose Ester-C Supreme for digestive comfort and the bioflavonoid cofactor profile.
Ester-C Supreme vs Naka Liposomal Vitamin C Softgels
Naka Liposomal Vitamin C uses a liposomal-style softgel with sodium ascorbate buffering for absorption focus. Ester-C Supreme uses calcium ascorbate (Ester-C®) with added bioflavonoids and quercetin in a capsule. Different buffering approaches, different cofactor stacks. Ester-C has more years of clinical history; the liposomal softgel is the newer absorption-tech approach. Choose based on preference and how each sits with your stomach.
Ester-C Supreme vs Acerola Cherry Whole-Food Vitamin C
Whole-food vitamin C (acerola, camu camu, amla) delivers a smaller dose of vitamin C alongside hundreds of co-occurring plant compounds — appealing if you prefer a food-based supplement philosophy. Ester-C Supreme uses a higher-potency synthesized vitamin C (in calcium ascorbate form) with isolated bioflavonoids and quercetin added back. Choose whole-food if you want the lowest-dose food-based approach; choose Ester-C for higher daily potency with researched cofactors.
What "Buffered" Vitamin C Means
- Straight ascorbic acid is acidic — pH around 2.5, similar to lemon juice. Some people experience heartburn, stomach upset, or loose stools at higher doses.
- Buffered forms bind ascorbic acid to a mineral (sodium ascorbate, calcium ascorbate, magnesium ascorbate). The acidity is neutralized, making the same vitamin C easier on a sensitive stomach.
- Ester-C® is a patented form of calcium ascorbate that also contains naturally occurring vitamin C metabolites (threonate, lyxonate, xylonate) — the same compounds your body makes when it uses ascorbic acid. The "Supreme" version adds citrus bioflavonoids and quercetin on top.
- Calcium note: calcium ascorbate contributes a small amount of calcium per dose. Most people don't notice; mention to your practitioner if you're on a calcium-restricted diet.
- Bioflavonoids and quercetin are plant compounds that occur naturally alongside vitamin C in citrus fruit. Often included in higher-quality vitamin C formulas for the synergy.
How To Use
Take 1 capsule daily, with or without food. For higher-dose routines, split the dose across the day (vitamin C absorption peaks at moderate doses; very high single doses are partly excreted).
Cautions: Consult your healthcare practitioner before use if you are pregnant or breastfeeding, have a history of kidney stones, hyperoxaluria, hemochromatosis, or are on a calcium-restricted diet. Vitamin C can interfere with some blood tests — let your practitioner know if you have bloodwork scheduled. Keep out of reach of children.
Frequently Asked Questions
âž• What's the difference between Ester-C and regular vitamin C?
âž• Why does it have bioflavonoids and quercetin?
âž• Can I take it on an empty stomach?
âž• How much vitamin C should I take daily?
âž• Is Ester-C okay with iron supplements?
âž• Can I take it with my zinc or other immune stack?
Pairs Well With
- Vitamin D — foundational immune support, especially in Canadian winters
- Zinc — classic immune-support stack with vitamin C
- Collagen — vitamin C is required for collagen synthesis
- Iron supplements — vitamin C improves iron absorption
💡 Subscribe & save up to 10% on every order — never run out of your daily supplements.
Compare Similar Products
- All Vitamin C Supplements
- Immune Support Supplements
- Antioxidants & Superfoods
- Cold & Flu Support
About Vitamart
Vitamart.ca is Canada's vitamin specialist. We've been selling vitamins and supplements to Canadian families since 2005, shipping from our Ontario warehouse to every province. We believe in quality products you trust at prices you love — no fancy packaging markups, no pushy upsells, just the vitamins you need at the lowest prices in Canada. Backed by our Low Price Guarantee: find a lower advertised price at a Canadian competitor and we'll beat it by 1¢.
Vitamins Lowest Prices.
More Images
SISU Ester-C Supreme 600mg Buffered Vitamin C Capsules, Calcium Ascorbate with Quercetin
SISU Ester-C Supreme 600mg Details
SISU Ester-C Supreme is buffered, non-acidic vitamin C built around the patented Ester-C® form (calcium ascorbate with naturally occurring vitamin C metabolites), plus added citrus bioflavonoids and quercetin. 600mg per capsule, designed to stay in white blood cells longer than standard ascorbic acid and to be gentler on the stomach. A sensible step up for adults who want a premium-tier vitamin C without going to liposomal liquid territory.
Vitamins Lowest Prices | Lowest Price in Canada — Guaranteed | Ships from Ontario across Canada
Quick Facts
| Brand | SISU |
| Form | Vegetarian capsule |
| Vitamin C | 600mg per capsule (Ester-C® calcium ascorbate) |
| pH | Non-acidic, buffered |
| Added cofactors | Citrus bioflavonoids + quercetin |
| Dose | 1 capsule daily (typical) |
| Diet | Vegetarian, gluten-free |
Who SISU Ester-C Supreme Is For
- You want a buffered, non-acidic vitamin C that's easier on the stomach
- You've tried regular ascorbic acid and found it caused heartburn or stomach upset
- You want vitamin C with cofactors (bioflavonoids, quercetin) like it occurs in nature, not isolated alone
- You want a once-daily dose that's reasonable, not megadose territory
- You want a recognized branded form (Ester-C®) backed by formulation research
- You want a capsule format — no powders, no liquids, no mixing
Who this product is NOT for: Anyone on a strict sodium-restricted or calcium-restricted diet should mention this to their practitioner — Ester-C is calcium ascorbate, so each serving contributes some calcium. Anyone with a history of kidney stones should consult their practitioner before higher-dose vitamin C use. If you want a true liquid liposomal C (Quicksilver or similar) for maximum absorption, that's a different category at a premium-tier price.
Vitamart's Take
Ester-C is a well-known buffered vitamin C — calcium ascorbate with the natural metabolites the body makes when it uses ascorbic acid. The selling point is gentler-on-the-stomach and longer cellular retention than straight ascorbic acid. Added bioflavonoids and quercetin make sense too — in nature, vitamin C never shows up isolated. Sensible everyday C for adults who want more than basic ascorbic acid tablets without going to liposomal liquid pricing.
How SISU Ester-C Supreme Compares
Ester-C Supreme vs Plain Ascorbic Acid
Plain ascorbic acid tablets are the lowest-cost route to vitamin C — fine if your stomach handles them and you don't need cofactors. Ester-C Supreme uses buffered calcium ascorbate (non-acidic) plus added bioflavonoids and quercetin. Choose plain ascorbic acid for budget daily use; choose Ester-C Supreme for digestive comfort and the bioflavonoid cofactor profile.
Ester-C Supreme vs Naka Liposomal Vitamin C Softgels
Naka Liposomal Vitamin C uses a liposomal-style softgel with sodium ascorbate buffering for absorption focus. Ester-C Supreme uses calcium ascorbate (Ester-C®) with added bioflavonoids and quercetin in a capsule. Different buffering approaches, different cofactor stacks. Ester-C has more years of clinical history; the liposomal softgel is the newer absorption-tech approach. Choose based on preference and how each sits with your stomach.
Ester-C Supreme vs Acerola Cherry Whole-Food Vitamin C
Whole-food vitamin C (acerola, camu camu, amla) delivers a smaller dose of vitamin C alongside hundreds of co-occurring plant compounds — appealing if you prefer a food-based supplement philosophy. Ester-C Supreme uses a higher-potency synthesized vitamin C (in calcium ascorbate form) with isolated bioflavonoids and quercetin added back. Choose whole-food if you want the lowest-dose food-based approach; choose Ester-C for higher daily potency with researched cofactors.
What "Buffered" Vitamin C Means
- Straight ascorbic acid is acidic — pH around 2.5, similar to lemon juice. Some people experience heartburn, stomach upset, or loose stools at higher doses.
- Buffered forms bind ascorbic acid to a mineral (sodium ascorbate, calcium ascorbate, magnesium ascorbate). The acidity is neutralized, making the same vitamin C easier on a sensitive stomach.
- Ester-C® is a patented form of calcium ascorbate that also contains naturally occurring vitamin C metabolites (threonate, lyxonate, xylonate) — the same compounds your body makes when it uses ascorbic acid. The "Supreme" version adds citrus bioflavonoids and quercetin on top.
- Calcium note: calcium ascorbate contributes a small amount of calcium per dose. Most people don't notice; mention to your practitioner if you're on a calcium-restricted diet.
- Bioflavonoids and quercetin are plant compounds that occur naturally alongside vitamin C in citrus fruit. Often included in higher-quality vitamin C formulas for the synergy.
How To Use
Take 1 capsule daily, with or without food. For higher-dose routines, split the dose across the day (vitamin C absorption peaks at moderate doses; very high single doses are partly excreted).
Cautions: Consult your healthcare practitioner before use if you are pregnant or breastfeeding, have a history of kidney stones, hyperoxaluria, hemochromatosis, or are on a calcium-restricted diet. Vitamin C can interfere with some blood tests — let your practitioner know if you have bloodwork scheduled. Keep out of reach of children.
Frequently Asked Questions
âž• What's the difference between Ester-C and regular vitamin C?
âž• Why does it have bioflavonoids and quercetin?
âž• Can I take it on an empty stomach?
âž• How much vitamin C should I take daily?
âž• Is Ester-C okay with iron supplements?
âž• Can I take it with my zinc or other immune stack?
Pairs Well With
- Vitamin D — foundational immune support, especially in Canadian winters
- Zinc — classic immune-support stack with vitamin C
- Collagen — vitamin C is required for collagen synthesis
- Iron supplements — vitamin C improves iron absorption
💡 Subscribe & save up to 10% on every order — never run out of your daily supplements.
Compare Similar Products
- All Vitamin C Supplements
- Immune Support Supplements
- Antioxidants & Superfoods
- Cold & Flu Support
About Vitamart
Vitamart.ca is Canada's vitamin specialist. We've been selling vitamins and supplements to Canadian families since 2005, shipping from our Ontario warehouse to every province. We believe in quality products you trust at prices you love — no fancy packaging markups, no pushy upsells, just the vitamins you need at the lowest prices in Canada. Backed by our Low Price Guarantee: find a lower advertised price at a Canadian competitor and we'll beat it by 1¢.
Vitamins Lowest Prices.
Product Information
Product Information
Shipping & Returns
Shipping & Returns
Description
SISU Ester-C Supreme 600mg Details
SISU Ester-C Supreme is buffered, non-acidic vitamin C built around the patented Ester-C® form (calcium ascorbate with naturally occurring vitamin C metabolites), plus added citrus bioflavonoids and quercetin. 600mg per capsule, designed to stay in white blood cells longer than standard ascorbic acid and to be gentler on the stomach. A sensible step up for adults who want a premium-tier vitamin C without going to liposomal liquid territory.
Vitamins Lowest Prices | Lowest Price in Canada — Guaranteed | Ships from Ontario across Canada
Quick Facts
| Brand | SISU |
| Form | Vegetarian capsule |
| Vitamin C | 600mg per capsule (Ester-C® calcium ascorbate) |
| pH | Non-acidic, buffered |
| Added cofactors | Citrus bioflavonoids + quercetin |
| Dose | 1 capsule daily (typical) |
| Diet | Vegetarian, gluten-free |
Who SISU Ester-C Supreme Is For
- You want a buffered, non-acidic vitamin C that's easier on the stomach
- You've tried regular ascorbic acid and found it caused heartburn or stomach upset
- You want vitamin C with cofactors (bioflavonoids, quercetin) like it occurs in nature, not isolated alone
- You want a once-daily dose that's reasonable, not megadose territory
- You want a recognized branded form (Ester-C®) backed by formulation research
- You want a capsule format — no powders, no liquids, no mixing
Who this product is NOT for: Anyone on a strict sodium-restricted or calcium-restricted diet should mention this to their practitioner — Ester-C is calcium ascorbate, so each serving contributes some calcium. Anyone with a history of kidney stones should consult their practitioner before higher-dose vitamin C use. If you want a true liquid liposomal C (Quicksilver or similar) for maximum absorption, that's a different category at a premium-tier price.
Vitamart's Take
Ester-C is a well-known buffered vitamin C — calcium ascorbate with the natural metabolites the body makes when it uses ascorbic acid. The selling point is gentler-on-the-stomach and longer cellular retention than straight ascorbic acid. Added bioflavonoids and quercetin make sense too — in nature, vitamin C never shows up isolated. Sensible everyday C for adults who want more than basic ascorbic acid tablets without going to liposomal liquid pricing.
How SISU Ester-C Supreme Compares
Ester-C Supreme vs Plain Ascorbic Acid
Plain ascorbic acid tablets are the lowest-cost route to vitamin C — fine if your stomach handles them and you don't need cofactors. Ester-C Supreme uses buffered calcium ascorbate (non-acidic) plus added bioflavonoids and quercetin. Choose plain ascorbic acid for budget daily use; choose Ester-C Supreme for digestive comfort and the bioflavonoid cofactor profile.
Ester-C Supreme vs Naka Liposomal Vitamin C Softgels
Naka Liposomal Vitamin C uses a liposomal-style softgel with sodium ascorbate buffering for absorption focus. Ester-C Supreme uses calcium ascorbate (Ester-C®) with added bioflavonoids and quercetin in a capsule. Different buffering approaches, different cofactor stacks. Ester-C has more years of clinical history; the liposomal softgel is the newer absorption-tech approach. Choose based on preference and how each sits with your stomach.
Ester-C Supreme vs Acerola Cherry Whole-Food Vitamin C
Whole-food vitamin C (acerola, camu camu, amla) delivers a smaller dose of vitamin C alongside hundreds of co-occurring plant compounds — appealing if you prefer a food-based supplement philosophy. Ester-C Supreme uses a higher-potency synthesized vitamin C (in calcium ascorbate form) with isolated bioflavonoids and quercetin added back. Choose whole-food if you want the lowest-dose food-based approach; choose Ester-C for higher daily potency with researched cofactors.
What "Buffered" Vitamin C Means
- Straight ascorbic acid is acidic — pH around 2.5, similar to lemon juice. Some people experience heartburn, stomach upset, or loose stools at higher doses.
- Buffered forms bind ascorbic acid to a mineral (sodium ascorbate, calcium ascorbate, magnesium ascorbate). The acidity is neutralized, making the same vitamin C easier on a sensitive stomach.
- Ester-C® is a patented form of calcium ascorbate that also contains naturally occurring vitamin C metabolites (threonate, lyxonate, xylonate) — the same compounds your body makes when it uses ascorbic acid. The "Supreme" version adds citrus bioflavonoids and quercetin on top.
- Calcium note: calcium ascorbate contributes a small amount of calcium per dose. Most people don't notice; mention to your practitioner if you're on a calcium-restricted diet.
- Bioflavonoids and quercetin are plant compounds that occur naturally alongside vitamin C in citrus fruit. Often included in higher-quality vitamin C formulas for the synergy.
How To Use
Take 1 capsule daily, with or without food. For higher-dose routines, split the dose across the day (vitamin C absorption peaks at moderate doses; very high single doses are partly excreted).
Cautions: Consult your healthcare practitioner before use if you are pregnant or breastfeeding, have a history of kidney stones, hyperoxaluria, hemochromatosis, or are on a calcium-restricted diet. Vitamin C can interfere with some blood tests — let your practitioner know if you have bloodwork scheduled. Keep out of reach of children.
Frequently Asked Questions
âž• What's the difference between Ester-C and regular vitamin C?
âž• Why does it have bioflavonoids and quercetin?
âž• Can I take it on an empty stomach?
âž• How much vitamin C should I take daily?
âž• Is Ester-C okay with iron supplements?
âž• Can I take it with my zinc or other immune stack?
Pairs Well With
- Vitamin D — foundational immune support, especially in Canadian winters
- Zinc — classic immune-support stack with vitamin C
- Collagen — vitamin C is required for collagen synthesis
- Iron supplements — vitamin C improves iron absorption
💡 Subscribe & save up to 10% on every order — never run out of your daily supplements.
Compare Similar Products
- All Vitamin C Supplements
- Immune Support Supplements
- Antioxidants & Superfoods
- Cold & Flu Support
About Vitamart
Vitamart.ca is Canada's vitamin specialist. We've been selling vitamins and supplements to Canadian families since 2005, shipping from our Ontario warehouse to every province. We believe in quality products you trust at prices you love — no fancy packaging markups, no pushy upsells, just the vitamins you need at the lowest prices in Canada. Backed by our Low Price Guarantee: find a lower advertised price at a Canadian competitor and we'll beat it by 1¢.
Vitamins Lowest Prices.
