ThorneVitamin D-5,000

The practical details.

Before you buy

Evidence & sources.

Do creatine, fish oil, vitamin D and magnesium work? Our evidence review grades the research as Mixed. That grade is about the claim, not about this product.

• CertificationNSF's Certified for Sport database lists "Thorne D-5,000" by Thorne as an immune aid/vitamin product. The listing shows an unflavored capsule, with a serving size of 1 capsule and package sizes of 60 and 120. It also includes a gluten free claim and 39 certified lot numbers. It was the only vitamin D entry found in NSF's Thorne results.^{2, 3} Checked in NSF's own database, not just taken from the mark on Thorne's page. The listing shows no product code, SKU, certification date or country of sale. It doesn't say what the program screens for. A sport certification concerns what's in the product, not health effects. You can match the lot number on your bottle to the listed lots.
• Manufacturer claimThorne's product page calls the product "NSF Certified for Sport." It says that mark signifies the product has been tested for compliance with label claims and for the absence of nearly 300 substances banned by major athletic organizations. Thorne says it tests each ingredient in Vitamin D-5,000 for identity, purity and potency. The page makes structure/function statements about teeth, bones, muscles, cardiovascular health, immune function and mood. It says these statements haven't been evaluated by the Food and Drug Administration. It also says the product isn't intended to diagnose, treat, cure or prevent any disease. It lists hypersensitivity to any ingredient as a contraindication and tells pregnant users to consult a health-care practitioner. It also says there are no known adverse interactions or contraindications at publication date.¹ These are Thorne's own statements, not evidence about effects. Thorne doesn't publish its test results on the page. For context, the VITAL trial summarized below found no significant reduction in cardiovascular events at 2,000 IU a day in older adults. It didn't test this product or the other statements. Thorne's statement about interactions also differs from the NIH ODS fact sheet. The fact sheet names orlistat, statins, steroids and thiazide diuretics as medications that may interact with vitamin D supplements or affect vitamin D levels.
• Independent testThe NIH Office of Dietary Supplements lists the adult tolerable upper intake level for vitamin D as 100 mcg (4,000 IU) a day. It defines that as the maximum daily intake unlikely to cause adverse health effects. The adult RDA is 600 IU (15 mcg) through age 70. After that, it's 800 IU (20 mcg). ODS notes that the Food and Nutrition Board said serum 25(OH)D above 125 nmol/L (50 ng/mL) can be associated with adverse effects. It also says excess vitamin D causes marked hypercalcemia (high blood calcium) and, in extreme cases, kidney failure, calcification of soft tissues and abnormal heart rhythms.⁵ A government reference summary, not a test of this product. Thorne's label dose of one 5,000 IU capsule a day is 1,000 IU above that upper level. That's why it's treated here as a clinician-advised strength. Whether to take it, and for how long, is a decision for a clinician.
• Independent testAs summarized by NIH ODS, the VITAL trial included 25,871 men aged 50 and older and women aged 55 and older. They were given 2,000 IU (50 mcg) of vitamin D3 a day (with or without omega-3s) or placebo for a median of 5.3 years. Rates of breast, prostate and colorectal cancer didn't differ significantly between the vitamin D and placebo groups. There was no significant reduction in heart attacks, strokes, coronary revascularization or deaths from cardiovascular causes. An ancillary analysis found no lower risk of total, hip or nonvertebral fractures.⁵ The trial tested 2,000 IU a day in older adults, not this product or a 5,000 IU dose. Its results don't show a benefit of that dose on these outcomes in that population.