Zahler PowerCal 1000 mg supplement bottle
Zahler

PowerCal 1000 mg Review

What We Researched
8 active ingredients analyzed · 5 inactive ingredients decoded · 3 brand certifications checked · Last updated: Aug 2026
91
Product Score Excellent
81
Brand Score Good

Two independent scores — the product and the brand behind it, never blended into one number. See our methodology.

Product Analysis

Transparency Excellent

Supplement Facts

IngredientAmount% DV
Calcium (as Calcium Carbonate, Calcium Citrate) 1000 mg 100%
Magnesium (as Magnesium Aspartate, Magnesium Oxide) 750 mg 187.5%
Zinc (as Zinc Citrate) 10 mg 66.67%
Manganese (as Manganese Citrate) 3 mg 150%
Vitamin D3 (as Cholecalciferol) 1000 IU 250%
Boron (as {boron} AAC) 3 mg
Strontium (as Strontium Citrate) 650 mg
Oat Straw 40 mg
Bioavailability Very Good

Absorption Rating

  • Calcium (as Calcium Carbonate, Calcium Citrate) Fair
  • Magnesium (as Magnesium Aspartate, Magnesium Oxide) Good
  • Zinc (as Zinc Citrate) Good
  • Manganese (as Manganese Citrate) Good
  • Vitamin D3 (as Cholecalciferol) Good
  • Boron (as {boron} AAC) Fair
  • Strontium (as Strontium Citrate) Good
  • Oat Straw Fair
Other Ingredients Excellent

Fillers & Additives

  • Stearic Acid
  • Magnesium Stearate
  • Croscarmellose Sodium
  • Cellulose
  • Silicon Dioxide
Efficacy Very Good

Dosage Analysis

  • Calcium (as Calcium Carbonate, Calcium Citrate) 1000 mg Effective
  • Magnesium (as Magnesium Aspartate, Magnesium Oxide) 750 mg High
  • Zinc (as Zinc Citrate) 10 mg Effective
  • Manganese (as Manganese Citrate) 3 mg Effective
  • Vitamin D3 (as Cholecalciferol) 1000 IU Effective
  • Boron (as {boron} AAC) 3 mg Effective
  • Strontium (as Strontium Citrate) 650 mg Effective
  • Oat Straw 40 mg Under-dosed

Supplement Facts

Ingredient Amount % Daily Value
Calcium (as Calcium Carbonate, Calcium Citrate) 1000 mg 100%
Magnesium (as Magnesium Aspartate, Magnesium Oxide) 750 mg 187.5%
Zinc (as Zinc Citrate) 10 mg 66.67%
Manganese (as Manganese Citrate) 3 mg 150%
Vitamin D3 (as Cholecalciferol) 1000 IU 250%
Boron (as {boron} AAC) 3 mg
Strontium (as Strontium Citrate) 650 mg
Oat Straw 40 mg

Other Ingredients

Inactive ingredients used in manufacturing. All rated for safety.

Stearic Acid Safe

Helps ingredients flow smoothly through manufacturing equipment.

Magnesium Stearate Safe

Prevents ingredients from sticking to manufacturing equipment during tableting.

Croscarmellose Sodium Safe

Helps tablets break apart and dissolve quickly in the stomach.

Cellulose Safe

Provides bulk and structure in tablets and capsules.

Silicon Dioxide Safe

Prevents clumping and ensures consistent dosing.

Brand Trust Report
Zahler

Founded 2005 · Brooklyn, NY, USA · 174 products · zahlers.com/

Certifications

3 certifications
Fda Gmp Inspections Verified Source
Kosher Certified Verified Source
NSF Certified Verified

Transparency

5 claims
Third Party Testing Claim — Claimed Source
In House Testing — Verified Source
Testing Lab Disclosure — True
Contains Proprietary Blend — True

Violation History

4 incidents
Prop 65 Lead2023-08-28Source
Lawsuit Trademark Infringement2022Source
Prop 65 Lead2021-12-09Source
Fda Warning A retailer was cited for making drug claims about a Zahler product.2017-04-17Source
Related Supplements
Frequently Asked Questions
Is Zahler PowerCal 1000 mg a good supplement?

Zahler PowerCal 1000 mg received a product quality score of 91/100 in GoodSupp's independent analysis, placing it in the top tier of supplements we've analyzed. The product contains 8 active ingredients with 45 servings per container. All 5 inactive ingredients (fillers, binders, capsule materials) are rated safe — a clean formulation with no flagged additives. The manufacturer, Zahler, holds a brand trust score of 81/100 with 3 verified certifications including Fda Gmp Inspections, Kosher Certified, NSF Certified.

What are the ingredients in Zahler PowerCal 1000 mg?

Zahler PowerCal 1000 mg contains 8 active ingredients: Calcium (as Calcium Carbonate, Calcium Citrate) (1000 mg), Magnesium (as Magnesium Aspartate, Magnesium Oxide) (750 mg), Zinc (as Zinc Citrate) (10 mg), Manganese (as Manganese Citrate) (3 mg), Vitamin D3 (as Cholecalciferol) (1000 IU), Boron (as {boron} AAC) (3 mg), and 2 more. Notable high-dose ingredients include Vitamin D3 at 250% DV. Each ingredient's dosage, form, and safety rating is analyzed independently in GoodSupp's full product breakdown.

Is Zahler PowerCal 1000 mg safe to take?

Zahler PowerCal 1000 mg has been analyzed for ingredient safety across all its components. All 5 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 Zahler a trustworthy supplement brand?

Zahler receives a brand trust score of 81/100 based on GoodSupp's independent analysis of certifications, regulatory history, and transparency practices. Founded in 2005 and headquartered in Brooklyn, NY, USA, the company offers 174 products in their lineup. They hold 3 verified certifications including Fda Gmp Inspections, Kosher Certified, NSF Certified. Third-party certifications are independently verified and indicate the brand meets specific quality, purity, and manufacturing standards. Note: Zahler has 4 historical regulatory incidents on record, which are factored into the trust score.

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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 — read our methodology. 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.