Vitamin D3 5000 IU

Name: Thorne Vitamin D3 5000 IU
Brand: Thorne
Price: 16.00 USD
Availability: InStock

The most well-studied supplement after creatine. Vitamin D deficiency affects an estimated 40-50% of adults worldwide. Thorne delivers the optimal D3 form at a clinical dose with no fillers, third-party tested.

89/ 100

Biorank Score

Independently ranked

89/ 100

Biorank Score

Independently ranked by Biorank Laboratories

Our Verdict

Best in Class

Vitamin D3 earns one of the highest evidence scores in our database because deficiency is genuinely common and supplementation has robust clinical support. Thorne's formulation uses pure D3 without unnecessary additives, is third-party tested (NSF certified), and delivers a clinically meaningful dose. At $0.27/day, it's among the best value supplements available.

Key Findings

40-50% of adults worldwide are vitamin D deficient — supplementation has strong evidence
5,000 IU is within the Endocrine Society's safe range and appropriate for deficient individuals
Thorne is NSF-certified with third-party testing — one of the most trustworthy brands
At $0.27/day, this is one of the best-value supplements in the entire database
Always test your levels before supplementing — excess vitamin D can cause hypercalcemia

Evidence Analysis

Vitamin D3 (cholecalciferol) is one of the most-studied nutrients in medicine. Deficiency is associated with increased risk of bone loss, immune dysfunction, cardiovascular disease, and depression. The Endocrine Society recommends 1,500-2,000 IU daily for adults, with higher doses (up to 5,000 IU) for those with documented deficiency. Holick (2007) and Autier & Gandini (2007) provide strong evidence for supplementation in deficient populations. 5,000 IU is well within the safe upper limit of 10,000 IU/day established by the Endocrine Society.

Ingredient Breakdown

Ingredient	Dose	Effective Dose	Adequacy	Verdict
Vitamin D3 (Cholecalciferol)	5000 IU (125mcg)	1000-5000 IU		Optimal

True Cost Analysis

Properly Dosed -- What You Pay Is What You Get

Listed Price

$0.27/serving

$8.10/month at 1 serving/day

True Cost Per Effective Dose

$0.27/effective dose

$8.10/month for effective dosing

Value Score

Excellent value

Save $4.20/month (52%)

by switching to NOW Foods Vitamin K2 MK-7 100mcg

Where It Falls Short

5,000 IU may be excessive for people who already have adequate vitamin D levels — always test before supplementing. Does not include Vitamin K2, which some evidence suggests improves calcium metabolism when taken with D3. Capsule form rather than liquid may have slightly lower absorption.