Vitamin D label accuracy
A 2013 JAMA Internal Medicine study (LeBlanc et al., PMID 23400578) found over-the-counter cholecalciferol products ranged from 52% to 135% of their labeled dose. ConsumerLab 2024 testing found products delivering up to 200% of labeled dose. Overconsumption risk is real because vitamin D is fat-soluble: excess accumulates and cannot be rapidly cleared. Primary prevention of cancer and cardiovascular disease is NOT established by the evidence (the VITAL trial, PMID 30415629, was null on both endpoints). The primary legitimate use for supplementation is correcting documented deficiency.
Evidence grade: well established in clinical research. This reflects the weight of current clinical literature; not medical advice.
Key Takeaways
- LeBlanc et al. (JAMA Internal Medicine, 2013, PMID 23400578) tested 15 OTC cholecalciferol products and found potency ranged from 52% to 135% of labeled dose. ConsumerLab 2024 testing found products at up to 200% of labeled dose, raising hypercalcemia risk for consumers stacking multiple D-containing supplements. Vitamin D is fat-soluble and accumulates in body fat; the NIH Tolerable Upper Intake Level for adults is 4,000 IU per day. Third-party certification (USP, NSF) tests for potency accuracy and reduces but does not eliminate this risk. We do not run these tests.
- Grade A evidence for deficiency correction: well established in clinical research.
- We show only products certified by a public third-party registry in the picks list. We do not run the tests.
- Attribution and dates are shown for every published test and certification we track.
- Check the certification registry link on each product; listings can be removed when a cert lapses.
LeBlanc et al. (JAMA Internal Medicine, 2013, PMID 23400578) tested 15 OTC cholecalciferol products and found potency ranged from 52% to 135% of labeled dose. ConsumerLab 2024 testing found products at up to 200% of labeled dose, raising hypercalcemia risk for consumers stacking multiple D-containing supplements. Vitamin D is fat-soluble and accumulates in body fat; the NIH Tolerable Upper Intake Level for adults is 4,000 IU per day. Third-party certification (USP, NSF) tests for potency accuracy and reduces but does not eliminate this risk. We do not run these tests.
Certified picks
Certified Vitamin D products
Vitamin D products certified by a third-party registry. We do not run the tests.
Herbaland Naturals Inc. Herbaland Gummies Vegan D3 & B12
No affiliate linkExpert stacks
What researchers and practitioners say
Each expert's stated dose and rationale, linked to their own words. Attribution only; no endorsement implied.
Blood level testing is the correct approach; dose should be calibrated to individual serum 25(OH)D levels rather than universally prescribed. Covers vitamin D with bloodwork guidance.
www.hubermanlab.com ↗Critiques standard trials for using insufficient doses (2,000 IU) that may not meaningfully shift blood levels; advocates individualized measurement-driven dosing rather than universal supplementation. Either no supplementation (if levels are adequate) or 5,000 IU if supplementation is warranted.
peterattiamd.com ↗Vitamin D functions as a steroid hormone, not a simple nutrient. Genetic variation in vitamin D metabolism makes testing essential. 70% of U.S. population has inadequate levels (below 30 ng/mL). Blood level target of 40-60 ng/mL based on all-cause mortality meta-analyses. 2,000 IU prevents and treats deficiency per large RCT review.
www.foundmyfitness.com ↗Blueprint focuses on biomarker-driven dosing rather than universal recommendations; Johnson has documented interest in vitamin D monitoring as part of his longevity protocol. Note: his personal daily dose is not explicitly stated in the public protocol document; 2,000 IU appears for a specific sub-population.
blueprint.bryanjohnson.com ↗Sources
- Over-the-counter and compounded vitamin D: is potency what we expect? (2013) observational
- Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease (2019) rct
- Vitamin D and Calcium for the Prevention of Fracture: A Systematic Review and Meta-analysis (2019) review
- Supplementation of vitamin D isolated or calcium-associated with bone remodeling and fracture risk in postmenopausal women without osteoporosis: A systematic review of randomized clinical trials (2023) review
- Effect of Vitamin D on falls: a meta-analysis (2004) review
- Association Between Vitamin D Supplementation and Fall Prevention (2022) review