Natural Factors Calcium & Magnesium Citrate with D3 supplement bottle
Natural Factors

Calcium & Magnesium Citrate with D3

What We Researched
7 active ingredients analyzed · 4 inactive ingredients decoded · 5 brand certifications checked · Last updated: Mar 2026
65
Product Score Fair
88
Brand Score Good

Product Analysis

Transparency Excellent

Supplement Facts

IngredientAmount% DV
Calcium (citrate) 250 mg
Magnesium (citrate/oxide) 250 mg
Potassium (citrate) 20 mg
Zinc (citrate) 5 mg
Manganese (citrate) 1 mg
Silicon from horsetail, (Equisetum arcense)(aerial) 100 mg
Vitamin D3 (cholecalciferol) 100 IU (2.5 mcg)
Bioavailability Very Good

Absorption Rating

  • Calcium (citrate) Good
  • Magnesium (citrate/oxide) Good
  • Potassium (citrate) Good
  • Zinc (citrate) Fair
  • Manganese (citrate) Good
  • Silicon from horsetail, (Equisetum arcense)(aerial) Fair
  • Vitamin D3 (cholecalciferol) Good
Other Ingredients Good

Fillers & Additives

  • Microcrystalline Cellulose
  • Coating (carbohydrate gum [cellulose], glycerin, titanium dioxide, polydextrose, triacetin, polyethylene glycol) High
  • Croscarmellose Sodium
  • Vegetable grade magnesium stearate (lubricant)
Efficacy Poor

Dosage Analysis

  • Calcium (citrate) 250 mg Under-dosed
  • Magnesium (citrate/oxide) 250 mg Effective
  • Potassium (citrate) 20 mg Under-dosed
  • Zinc (citrate) 5 mg Under-dosed
  • Manganese (citrate) 1 mg Under-dosed
  • Silicon from horsetail, (Equisetum arcense)(aerial) 100 mg High
  • Vitamin D3 (cholecalciferol) 100 IU (2.5 mcg) Under-dosed

Supplement Facts

Ingredient Amount % Daily Value
Calcium (citrate) 250 mg
Magnesium (citrate/oxide) 250 mg
Potassium (citrate) 20 mg
Zinc (citrate) 5 mg
Manganese (citrate) 1 mg
Silicon from horsetail, (Equisetum arcense)(aerial) 100 mg
Vitamin D3 (cholecalciferol) 100 IU (2.5 mcg)

Other Ingredients

Inactive ingredients used in manufacturing. All rated for safety.

Microcrystalline Cellulose Safe

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

Coating (carbohydrate gum [cellulose], glycerin, titanium dioxide, polydextrose, triacetin, polyethylene glycol) Unknown
Croscarmellose Sodium Safe

Helps tablets break apart and dissolve quickly in the stomach.

Vegetable grade magnesium stearate (lubricant) Unknown
Brand Trust Report
Natural Factors

Founded 1950 · Coquitlam, British Columbia, Canada · 390 products · naturalfactors.com

Certifications

5 certifications
B Corp Certified Verified Source
Usp Verified Verified Source
Fda Gmp Inspections Verified Source
Non Gmo Project Verified Source
Usda Organic Verified Source

Transparency

4 claims
Third Party Testing Claim — Verified Source
Testing Lab Disclosure — Verified Source
In House Testing — Verified Source

Violation History

5 incidents
Prop 65 Lead2025-10-31Source
Recall Hi Potency B Complex, RevitalX, Super Multi® IRON FREE2024-07-19Source
Lawsuit Products labeled as containing glucosamine sulfate did not contain the ingredient.2021Source
Prop 65 Lead2016-01-13Source
Recall Natural Factors L-Arginine 500mg2006-04-05Source
Related Supplements
Frequently Asked Questions
Is Natural Factors Calcium & Magnesium Citrate with D3 a good supplement?

Natural Factors Calcium & Magnesium Citrate with D3 received a product quality score of 65/100 in GoodSupp's independent analysis, suggesting some areas that could be improved. The product contains 7 active ingredients Of the 4 inactive ingredients, 2 are rated safe and 0 are flagged for review. The manufacturer, Natural Factors, holds a brand trust score of 88/100 with 5 verified certifications including B Corp Certified, Usp Verified, Fda Gmp Inspections, Non Gmo Project.

What are the ingredients in Natural Factors Calcium & Magnesium Citrate with D3?

Natural Factors Calcium & Magnesium Citrate with D3 contains 7 active ingredients: Calcium (citrate) (250 mg), Magnesium (citrate/oxide) (250 mg), Potassium (citrate) (20 mg), Zinc (citrate) (5 mg), Manganese (citrate) (1 mg), Silicon from horsetail, (Equisetum arcense)(aerial) (100 mg), and 1 more. Each ingredient's dosage, form, and safety rating is analyzed independently in GoodSupp's full product breakdown.

Is Natural Factors Calcium & Magnesium Citrate with D3 safe to take?

Natural Factors Calcium & Magnesium Citrate with D3 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 Natural Factors a trustworthy supplement brand?

Natural Factors receives a brand trust score of 88/100 based on GoodSupp's independent analysis of certifications, regulatory history, and transparency practices. Founded in 1950 and headquartered in Coquitlam, British Columbia, Canada, the company offers 390 products in their lineup. They hold 5 verified certifications including B Corp Certified, Usp Verified, Fda Gmp Inspections, Non Gmo Project. Third-party certifications are independently verified and indicate the brand meets specific quality, purity, and manufacturing standards. Note: Natural Factors has 5 historical regulatory incidents on record, which are factored into the trust score.

What is magnesium good for?

Magnesium Good For is a topic many supplement consumers ask about. In the context of dietary supplements, understanding magnesium good for helps you make more informed choices about what you put in your body. The quality and form of ingredients matters significantly — two products listing the same ingredient can differ dramatically in bioavailability and effectiveness. GoodSupp analyzes over 250,000 supplement products to help consumers understand exactly what's in their supplements and whether the formulation meets quality standards.

How much magnesium per day?

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 is zinc good for?

Zinc Good For is a topic many supplement consumers ask about. In the context of dietary supplements, understanding zinc good for helps you make more informed choices about what you put in your body. The quality and form of ingredients matters significantly — two products listing the same ingredient can differ dramatically in bioavailability and effectiveness. GoodSupp analyzes over 250,000 supplement products to help consumers understand exactly what's in their supplements and whether the formulation meets quality standards.

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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.