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Thorne vs Sports Research Vitamin D3 (2026)

Last reviewed Jul 2026|2 products compared|View all Vitamin D3 products

Disclosure: We earn commissions on purchases made through our links. This never influences our scores. Editorial policy

The Verdict

Sports Research edges Thorne on our rubric, 87 to 85 on our 0-100 execution score, and it is meaningfully cheaper - about $0.05 per day versus Thorne's $0.33 per day at 5000 IU, roughly a 6x cost difference for the same vitamin. Both carry a top-tier sport certification (Informed Sport for Sports Research, NSF Certified for Sport for Thorne). For most buyers Sports Research is the better value by a wide margin. Thorne makes sense only if your testing protocol specifically requires NSF Certified for Sport.

85/100

Thorne Vitamin D-5,000

Thorne

Cost/day:$0.33Dose:5000IUForm:cholecalciferol (D3)...Price:$20.00
Third-party tested (NSF Certified for Sport)
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87/100

Sports Research Vitamin D3 5000 IU with Coconut Oil

Sports Research

Cost/day:$0.05Dose:5000IUForm:cholecalciferol (D3)...Price:$17.95
Third-party tested (Informed Sport Certified, IGEN Non-GMO Tested)
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Head-to-Head Comparison

Category
Thorne Vitamin D-5,000
Thorne
Sports Research Vitamin D3 5000 IU with Coconut Oil
Sports Research
Brand Score85/10087/100Winner
Dosing & Form25/25Winner25/25
Purity25/25Winner20/25
Value12/2520/25Winner
Transparency23/25Winner22/25
Cost/Day$0.33$0.05Winner
Dose/Serving5000IU5000IU
Formcholecalciferol (D3) capsulecholecalciferol (D3) with coconut MCT oil, mini softgel
Third-Party Tested✓ Yes✓ Yes
Proprietary BlendNoNo

Why This Comparison Matters

Both Thorne and Sports Research carry serious sport-testing credentials on their 5000 IU vitamin D3, which makes this a useful matchup for drug-tested athletes and anyone who wants a certification behind the bottle. Thorne is NSF Certified for Sport; Sports Research is Informed Sport Certified. Both are legitimate banned-substance programs.

The active ingredient is the same cholecalciferol at the same 5000 IU dose, so certification and cost are what separate them. Sports Research delivers its D3 in coconut MCT oil; Thorne uses a straightforward capsule.

We scored both on evidence, quality, cost per effective dose, and transparency.

Detailed Score Breakdown

85/100

Thorne Vitamin D-5,000

Thorne

Dosing & Form
25/25

Higher-dose D3 appropriate for those with documented deficiency or higher body weight

Purity
25/25

NSF Certified for Sport - verified free of 270+ banned substances. Thorne manufacturing exceeds FDA cGMP standards.

Value
12/25

$0.33/day - the most expensive D3 here; the premium buys NSF Certified for Sport status, not a higher dose

Transparency
23/25

Exemplary label transparency. No unnecessary excipients, capsule form (not softgel), source and form clearly identified.

Dose/Serving5000IU
Formcholecalciferol (D3) capsule
Price$20.00(60 servings)
Cost/Effective Dose$0.33/day
Third-party tested: NSF Certified for SportNo proprietary blendGMP certified

NSF Certified for Sport makes this the go-to for competitive athletes. Clean capsule with minimal excipients.

87/100

Sports Research Vitamin D3 5000 IU with Coconut Oil

Sports Research

Dosing & Form
25/25

Standard D3 cholecalciferol with coconut oil for absorption

Purity
20/25

Informed Sport Certified (tested for banned substances). IGEN Non-GMO Tested. Not USP or NSF.

Value
20/25

$0.05/day - slightly above the cheapest options but not expensive

Transparency
22/25

Clean label. Coconut MCT oil carrier specified. Form and source clearly identified. No proprietary blends.

Dose/Serving5000IU
Formcholecalciferol (D3) with coconut MCT oil, mini softgel
Price$17.95(360 servings)
Cost/Effective Dose$0.05/day
Third-party tested: Informed Sport Certified, IGEN Non-GMO TestedNo proprietary blendGMP certified

Mini softgels are easier to swallow. Informed Sport certification suitable for athletes.

How We Compared These Products

Every product in our database is scored on four equally-weighted pillars: dosing accuracy and form quality, purity verification (third-party testing), cost per clinically effective dose (not cost per pill), and label transparency. Each pillar is worth 25 points for a total of 100.

Cost per effective dose is calculated using the clinically studied dose from published research, not the manufacturer's suggested serving. If a product requires multiple servings to reach the dose used in clinical trials, that cost is reflected in the value score.

For a full explanation of our scoring methodology, see our methodology page. Prices were last checked on the dates listed for each product and may have changed.

Frequently Asked Questions

Is Thorne or Sports Research vitamin D3 better?

Sports Research scores slightly higher on our rubric (87 vs 85 on our 0-100 execution score) and costs far less - about $0.05 per day versus Thorne's $0.33 per day for the same 5000 IU of cholecalciferol. Both carry a legitimate banned-substance certification (Informed Sport for Sports Research, NSF Certified for Sport for Thorne). For most people Sports Research is the smarter buy; Thorne is worth it only if you specifically need NSF Certified for Sport.

Does the carrier oil (coconut vs capsule) matter for vitamin D3?

Barely. Vitamin D3 is fat-soluble and absorbs well with any dietary fat, so Sports Research's coconut MCT oil softgel and Thorne's capsule perform similarly in practice. Taking either with a meal that contains some fat is more important than the specific carrier. The carrier is a minor preference, not an absorption dealbreaker.

Is 5000 IU of vitamin D3 too much?

For most adults it is within safe limits. 5000 IU (125 mcg) sits above the RDA but below the Institute of Medicine's tolerable upper intake of 4000 IU only if taken indefinitely without monitoring - many people use 5000 IU short-term to correct a deficiency confirmed by a 25(OH)D blood test, then step down. If you are supplementing long-term, base the dose on bloodwork rather than guesswork.

We earn commissions on purchases made through our links. This never influences our scores or recommendations. See our editorial policy.

FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. Dietary supplements are not intended to diagnose, treat, cure, or prevent any disease. Always consult with a qualified healthcare professional before starting any supplement regimen.