Kirkman Labs Buffered Vitamin C Powder, Passionfruit, 7 oz (198.5 g) supplement bottle
Kirkman Labs

Buffered Vitamin C Powder, Passionfruit, 7 oz (198.5 g)

What We Researched
2 active ingredients analyzed · 2 inactive ingredients decoded · 1 brand certification checked · 3 retailers compared · Last updated: Mar 2026
87
Product Score Good
81
Brand Score Good

Product Analysis

Transparency Excellent

Supplement Facts

IngredientAmount% DV
Vitamin C (as Sodium, Potassium, & Magnesium Ascorbates, Ascorbic Acid) 1,100 mg 1222%
Sodium (from Sodium Ascorbate) 75 mg 3%
Bioavailability Excellent

Absorption Rating

  • Vitamin C (as Sodium, Potassium, & Magnesium Ascorbates, Ascorbic Acid) Good
  • Sodium (from Sodium Ascorbate) Good
Other Ingredients Excellent

Fillers & Additives

  • Natural passionfruit flavor
  • Stevia Leaf Extract
Efficacy Fair

Dosage Analysis

  • Vitamin C (as Sodium, Potassium, & Magnesium Ascorbates, Ascorbic Acid) 1,100 mg Effective
  • Sodium (from Sodium Ascorbate) 75 mg Under-dosed

Supplement Facts

Ingredient Amount % Daily Value
Vitamin C (as Sodium, Potassium, & Magnesium Ascorbates, Ascorbic Acid) 1,100 mg 1222%
Sodium (from Sodium Ascorbate) 75 mg 3%

Other Ingredients

Inactive ingredients used in manufacturing. All rated for safety.

Natural passionfruit flavor Unknown
Stevia Leaf Extract Safe

Provides sweetness without calories or blood sugar impact.

Price Comparison

Price History

Tracked across major retailers. Updated periodically.

$23$22$21$20$19 Mar 12 $21.00
iHerb

Prices shown at time of last check. Click a retailer to see current price. GoodSupp is not affiliated with any retailer.

Brand Trust Report
Kirkman Labs

Founded 1949 · Lake Oswego, Oregon, U.S. · 74 products · kirkmangroup.com

Certifications

1 certification
Fda Gmp Inspections Verified Source

Transparency

5 claims
Third Party Testing Claim — Verified Source
Coa Availability — Claimed Source
Testing Lab Disclosure — Claimed Source
In House Testing — Verified Source

Violation History

1 incident
Fda Warning Marketing unapproved new drugs and misbranded drugs (sodium fluoride products).2016-01-13Source
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Frequently Asked Questions
Is Kirkman Labs Buffered Vitamin C Powder, Passionfruit a good supplement?

Kirkman Labs Buffered Vitamin C Powder, Passionfruit, 7 oz (198.5 g) received a product quality score of 87/100 in GoodSupp's independent analysis, indicating strong overall quality. The product contains 2 active ingredients with 158 servings per container. Of the 2 inactive ingredients, 1 are rated safe and 0 are flagged for review. The manufacturer, Kirkman Labs, holds a brand trust score of 81/100 with 1 verified certifications including Fda Gmp Inspections.

What are the ingredients in Kirkman Labs Buffered Vitamin C Powder, Passionfruit?

Kirkman Labs Buffered Vitamin C Powder, Passionfruit contains 2 active ingredients: Vitamin C (as Sodium, Potassium, & Magnesium Ascorbates, Ascorbic Acid) (1,100 mg), Sodium (from Sodium Ascorbate) (75 mg). Notable high-dose ingredients include Vitamin C at 1222% DV. Each ingredient's dosage, form, and safety rating is analyzed independently in GoodSupp's full product breakdown.

Is Kirkman Labs Buffered Vitamin C Powder, Passionfruit safe to take?

Kirkman Labs Buffered Vitamin C Powder, Passionfruit, 7 oz (198.5 g) has been analyzed for ingredient safety across all its components. Always consult your healthcare provider before starting any new supplement, especially if you take medications or have underlying health conditions.

Is Kirkman Labs a trustworthy supplement brand?

Kirkman Labs receives a brand trust score of 81/100 based on GoodSupp's independent analysis of certifications, regulatory history, and transparency practices. Founded in 1949 and headquartered in Lake Oswego, Oregon, U.S., the company offers 74 products in their lineup. They hold 1 verified certifications including Fda Gmp Inspections. Third-party certifications are independently verified and indicate the brand meets specific quality, purity, and manufacturing standards. Note: Kirkman Labs has 1 historical regulatory incident on record, which are factored into the trust score.

How much vitamin d3 should i take daily?

The optimal dosage depends on your individual health needs, age, sex, and current nutrient levels. Recommended daily amounts are established by health authorities but may vary from therapeutic doses used in clinical research. It's important to check the Supplement Facts label for the exact amount per serving and compare it against the % Daily Value. Some supplements provide mega-doses well above the Daily Value, which may not be necessary and in some cases could be harmful — particularly for fat-soluble vitamins (A, D, E, K) that accumulate in the body. GoodSupp's efficacy analysis evaluates whether a product's dosages align with clinically studied amounts. Always consult your healthcare provider for personalized dosage recommendations.

What does vitamin d do?

This is an important question for supplement consumers. The dietary supplement industry is largely self-regulated, which means product quality, ingredient transparency, and safety practices vary significantly between brands and products. The most reliable way to evaluate any supplement is to check for third-party testing certifications, review the full ingredient list and dosages, and research the brand's regulatory track record. GoodSupp's database of over 250,000 analyzed products provides independent quality scores, ingredient safety ratings, and brand trust reports to help you make evidence-based decisions.

How much vitamin d3 per day for a woman?

The optimal dosage depends on your individual health needs, age, sex, and current nutrient levels. Recommended daily amounts are established by health authorities but may vary from therapeutic doses used in clinical research. It's important to check the Supplement Facts label for the exact amount per serving and compare it against the % Daily Value. Some supplements provide mega-doses well above the Daily Value, which may not be necessary and in some cases could be harmful — particularly for fat-soluble vitamins (A, D, E, K) that accumulate in the body. GoodSupp's efficacy analysis evaluates whether a product's dosages align with clinically studied amounts. Always consult your healthcare provider for personalized dosage recommendations.

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Disclaimer: GoodSupp provides independent supplement quality analysis for informational purposes only. Scores are generated algorithmically based on ingredient profiles, brand certifications, and public records. This is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Product data is sourced from manufacturer labels and public databases. GoodSupp is not affiliated with any supplement brand.