Which vitamin D3 brands are third-party tested?
Our picks, by labeled strength, with a link to buy them: see where to buy. A strength with nothing certified at it has no pick, and is not listed there.
13 of the 52 vitamin D3 and D3 + K2 products we track have their exact package named by a certifier. Another 1 comes from a product line a certifier lists, but at a package size the certificate does not name. The remaining 38 appear in no database we searched.
A certifier lists a specific package against each certificate. A brand can sell the same formula in several sizes, or several flavors, and have one of them listed, so “this brand is NSF certified” can be true while the tub in your hand is not the tub NSF tested. The middle group below is that gap.
Strength is the trap in this category. One brand's 5,000 IU softgel can be named by a certificate while its 1,000 IU and 10,000 IU softgels on the same page are not, and the same goes for count: a 500-count bottle named, the 365-count not.
Certifier names this exact package, 13
The strongest evidence available here. For NSF, the listing names the package size sold; it was opened, its package text recorded, and its ID is on the product page. For USP, which names products rather than packages, the product is in USP's directory and the USP Verified Mark is on this package's own label, and both are on the product page.
Listed, but not at this size, 1
The brand and product appear in the database at a different package size. Not a failure, and not a confirmation either.
| Product | Type | Per 1,000 IU | Certificate |
|---|---|---|---|
| BulkSupplements.com Vitamin D3 5,000 IU Softgels (365 count) | D3 | 1.37¢ | 1823428 |
Searched, and not found, 38
Not listed by NSF Certified for Sport when we read its full directory. These programs certify what a company submits to them, so a product can be absent from the database simply because it was never entered, which is not a finding against it.
NSF Certified for Sport, the Informed programs' published product lists, the IFOS directory and USP's directory are each read in full, and each product page names the day. A product missing from this page has not failed a check. It has not had one.
Where to buy: the picks, by labeled strength
The pick is the cheapest certified product, at the exact package sold where the certifier names packages, with no adverse finding on record, a price its retailer let us read recently, and no more than a year’s supply at the label’s serving; per delivered dose where the retailer publishes a delivery rate. Where none does, it is the cheapest such product before delivery, and it says how far the order is from free delivery. It is the same pick the category page shows.
How these lines are chosen
Among 10 products and 10 retailer listings we track; Amazon and Walmart are not included. A month is thirty doses of the size in the heading, priced the same way as the per-dose figure beside it. “Delivery known” ranks only products whose retailer publishes a delivery rate; a cheaper product with an unpublished rate is on its own line, or in the full list below.
How these lines are chosen
Among 6 products and 6 retailer listings we track; Amazon and Walmart are not included. A month is thirty doses of the size in the heading, priced the same way as the per-dose figure beside it. “Delivery known” ranks only products whose retailer publishes a delivery rate; a cheaper product with an unpublished rate is on its own line, or in the full list below.
How these lines are chosen
Among 11 products and 11 retailer listings we track; Amazon and Walmart are not included. A month is thirty doses of the size in the heading, priced the same way as the per-dose figure beside it. “Delivery known” ranks only products whose retailer publishes a delivery rate; a cheaper product with an unpublished rate is on its own line, or in the full list below.
How these lines are chosen
Among 2 products and 2 retailer listings we track; Amazon and Walmart are not included. A month is thirty doses of the size in the heading, priced the same way as the per-dose figure beside it. “Delivery known” ranks only products whose retailer publishes a delivery rate; a cheaper product with an unpublished rate is on its own line, or in the full list below. No product here publishes a delivery rate below its free-delivery threshold, so the pick is priced before delivery.
Full comparison of every product in this category: Vitamin D3. Every question we answer: the question index.
What this rests on: prices we last recorded at the retailer named on each product page, which go stale, and each page says when it was checked; the products we track, not every product sold, and Amazon and Walmart are not among the stores; listings and labels read at the source, each linked from the page. Found an error? Tell us. The full method: How we compare.