Vitamin D3 questions
10 questions about vitamin D3, each answered from the 67 products we track, priced per 1,000 IU where a price is on record, and from the certifier listings behind them, recomputed on every build. Where the answer is “we do not know”, it says so. See every vitamin D3 product.
Which vitamin D3 brands are third-party tested?
Every vitamin D3 and D3 + K2 we track, grouped by whether a certifier lists the exact bottle, another size, or nothing we found. Absence is not a verdict.
Vitamin D3 1,000 IU vs 5,000 IU: which costs less?
What each strength costs per 1,000 IU, read from the labels and the prices we hold. A price comparison only: we do not say which strength anyone should take.
How much more does vitamin D3 with K2 cost?
What adding K2 costs, brand by brand at the same strength: bottle against bottle where a brand sells the same count both ways, and per 1,000 IU of D3 where it does not.
Is BulkSupplements vitamin D3 NSF certified?
Which BulkSupplements D3 softgels NSF Certified for Sport names, at which bottle sizes, and which it does not, with the listing IDs.
Is Momentous vitamin D3 NSF certified?
Which Momentous vitamin D3 bottles we price NSF Certified for Sport names at the exact package. The listing IDs, the strengths and what each covers.
Is Thorne vitamin D NSF certified?
Thorne D-1,000, D-5,000, D-10,000 and the liquids checked against NSF Certified for Sport: which bottles a listing names, with the listing IDs.
What is the cheapest NSF certified vitamin D3?
Every plain vitamin D3 we track whose exact bottle NSF names in its Certified for Sport database, compared on cost per 1,000 IU within each strength, with D3 + K2 ranked apart.
What is the cheapest vitamin D3?
The cheapest plain vitamin D3 at each labeled strength, priced per 1,000 IU from its own label, with whether that package is third-party tested.
Is a vitamin D3 label in mcg the same as one in IU?
Convert vitamin D3 mcg to IU and back, checked against every label we price: one mcg is 40 IU, so 25 mcg is 1,000 IU and 125 mcg is 5,000 IU.
Is Nature Made vitamin D3 USP Verified?
Nature Made vitamin D3, every strength and count we price, checked against USP’s Verified directory and the USP Verified Mark on each bottle’s label.
Questions that span every supplement
Do third-party tested supplements cost more?
Per category, the cheapest product we track beside the cheapest a certifier names at the exact package, if any, within one format and, where it matters, one strength.
Is BulkSupplements third party tested?
Every BulkSupplements product we track, by whether a certifier names the exact package sold, only another size, or nothing we found. With listing IDs.
Is Thorne third party tested?
Every Thorne product we price, checked in NSF’s Certified for Sport database: which listing names the exact package sold, with the listing IDs.
Is Core Med Science third party tested?
Every Core Med Science product we price, checked in NSF’s Certified for Sport database: which listing names the exact package sold, and the IDs.
Is Optimum Nutrition third party tested?
Every Optimum Nutrition product we track, checked in the certifier databases: what each listing covers, package by package, with the listing IDs.
Is Momentous third party tested?
Every Momentous product we price, checked in NSF’s Certified for Sport database: where a listing names the exact package, and where it names another size.
Is BPN third party tested?
Every Bare Performance Nutrition product we price, checked in NSF’s Certified for Sport database: which package each listing names, and which it does not.
Which supplements are NSF Certified for Sport?
Every package we price that NSF names in its Certified for Sport database, by category, with the listing IDs and what each listing actually covers.
Do supplement prices actually change?
We keep every price reading we take: daily where a store can be read automatically, less often where it is read by hand. Which prices have moved since we started, which have not, and by how much.
How many capsules is one serving?
How many pills the label calls one serving, across every capsule, tablet and softgel we have a price for, and what that does to the count on the front of the bottle.
Is MegaFood third party tested?
Every MegaFood product we price, checked in the NSF, USP and Informed databases: which listing names the exact package sold, and which we found no listing for.
Is Evogen Nutrition third party tested?
Every Evogen Nutrition product we price, checked in NSF’s Certified for Sport database and others: which listing names the exact package sold, with the listing IDs.
Is BUBS Naturals third party tested?
Every BUBS Naturals product we price, checked in NSF’s Certified for Sport database: which listing names the exact package sold, with the listing IDs.
Is Sports Research third party tested?
Every Sports Research product we track, checked in the certifier databases: which program lists each one, and which no database we searched lists.
Is Nature Made third party tested?
Every Nature Made product we price, checked against USP’s Verified Products directory, NSF’s Certified for Sport database and its own label, product by product.
Questions about something else: Creatine Monohydrate · Magnesium · Omega-3 · Whey Protein · Plant Protein · Collagen Peptides · Vitamin B12 · Vitamin C · Zinc. Or every question on one page.
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.