Certification status
USP Verified
Kirkland Signature Kirkland Signature Extra Strength D3 50 mcg Softgels
Kirkland Signature's Extra Strength Vitamin D3 delivers 50 µg (2,000 IU) per softgel — Costco's own-brand value option. USP Verified for identity, purity and potency, which is not a banned-substance test. £12.39 on Amazon UK, rated 4.7 from over 520 reviews.
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Why this certification matters
- USP Verified
- USP Verified products meet the United States Pharmacopeia standards for ingredient identity, potency, and manufacturing quality.
Frequently asked questions
- How much vitamin D per softgel?
- 50 µg, equivalent to 2,000 IU.
- What does USP Verified mean?
- USP independently tests for identity, purity and potency — confirming the label. It is not a banned-substance certification.
- Is Kirkland good value?
- It's Costco's own brand, generally positioned as a lower-cost option; £12.39 on Amazon UK here.
- How does 2,000 IU compare to guidance?
- It's above the NHS general 400 IU a day — a common maintenance strength for adults topping up vitamin D.
