GNC Vitamin D-3 25 mcg (1000 IU) supplement bottle
GNC

Vitamin D-3 25 mcg (1000 IU)

What We Researched
2 active ingredients analyzed · 6 inactive ingredients decoded · 5 brand certifications checked · 2 retailers compared · Last updated: Mar 2026
87
Product Score Good
88
Brand Score Good

Product Analysis

Transparency Excellent

Supplement Facts

IngredientAmount% DV
Vitamin D (as Cholecalciferol, Vitamin D3) 25 mcg 125%
Calcium 74 mg 6%
Bioavailability Excellent

Absorption Rating

  • Vitamin D (as Cholecalciferol, Vitamin D3) Good
  • Calcium Good
Other Ingredients Excellent

Fillers & Additives

  • Dicalcium Phosphate
  • Microcrystalline Cellulose
  • Croscarmellose Sodium
  • Stearic Acid
  • Magnesium Stearate
  • Silicon Dioxide
Efficacy Fair

Dosage Analysis

  • Vitamin D (as Cholecalciferol, Vitamin D3) 25 mcg Effective
  • Calcium 74 mg Under-dosed

Supplement Facts

Ingredient Amount % Daily Value
Vitamin D (as Cholecalciferol, Vitamin D3) 25 mcg 125%
Calcium 74 mg 6%

Other Ingredients

Inactive ingredients used in manufacturing. All rated for safety.

Dicalcium Phosphate Safe

Serves as both a filler and a supplemental source of calcium and phosphorus.

Microcrystalline Cellulose Safe

Adds bulk to small-dose supplements to make tablets/capsules a manageable size.

Croscarmellose Sodium Safe

Helps tablets break apart and dissolve quickly in the stomach.

Stearic Acid Safe

Helps ingredients flow smoothly through manufacturing equipment.

Magnesium Stearate Safe

Prevents ingredients from sticking to manufacturing equipment during tableting.

Silicon Dioxide Safe

Prevents clumping and ensures consistent dosing.

Price Comparison

Price History

Tracked across major retailers. Updated periodically.

$22$21$20$19$18 Mar 12 $19.99
GNC

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

Brand Trust Report
GNC

Founded 1935 · Pittsburgh, Pennsylvania, USA · 200 products · gnc.com

Certifications

5 certifications
Informed Sport Verified Source
Consumerlab Verified Source
Fda Gmp Inspections Verified Source
Usda Organic Verified Source
Vegan Certified Verified Source

Transparency

3 claims
Third Party Testing Claim — Verified Source
Testing Lab Disclosure — Verified Source
In House Testing — Claimed
Related Supplements
Frequently Asked Questions
Is GNC Vitamin D-3 25 mcg (1000 IU) a good supplement?

GNC Vitamin D-3 25 mcg (1000 IU) received a product quality score of 87/100 in GoodSupp's independent analysis, indicating strong overall quality. The product contains 2 active ingredients All 6 inactive ingredients (fillers, binders, capsule materials) are rated safe — a clean formulation with no flagged additives. The manufacturer, GNC, holds a brand trust score of 88/100 with 5 verified certifications including Informed Sport, Consumerlab, Fda Gmp Inspections, Usda Organic.

What are the ingredients in GNC Vitamin D-3 25 mcg (1000 IU)?

GNC Vitamin D-3 25 mcg (1000 IU) contains 2 active ingredients: Vitamin D (as Cholecalciferol, Vitamin D3) (25 mcg), Calcium (74 mg). Each ingredient's dosage, form, and safety rating is analyzed independently in GoodSupp's full product breakdown.

Is GNC Vitamin D-3 25 mcg (1000 IU) safe to take?

GNC Vitamin D-3 25 mcg (1000 IU) has been analyzed for ingredient safety across all its components. All 6 inactive ingredients — including capsule materials, fillers, and binders — are rated safe based on regulatory data and published safety research. This is a clean formulation with no controversial additives. Always consult your healthcare provider before starting any new supplement, especially if you take medications or have underlying health conditions.

Is GNC a trustworthy supplement brand?

GNC receives a brand trust score of 88/100 based on GoodSupp's independent analysis of certifications, regulatory history, and transparency practices. Founded in 1935 and headquartered in Pittsburgh, Pennsylvania, USA, the company offers 200 products in their lineup. They hold 5 verified certifications including Informed Sport, Consumerlab, Fda Gmp Inspections, Usda Organic. Third-party certifications are independently verified and indicate the brand meets specific quality, purity, and manufacturing standards. No regulatory violations or FDA warning letters were found in our research.

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.