vitamin-d
Vitamin D-1,000
Thorne is the gold standard for clinical purity, holding an NSF Certified for Sport designation which ensures the product is free from over 200 banned substances and contaminants. Their D3 is formulated without unnecessary fillers, using only high-quality medium-chain triglyceride (MCT) oil as a carrier for optimal absorption.
Quality & Materials
Contains Vitamin D3 (cholecalciferol) sourced from lanolin, suspended in MCT oil. It is free from gluten, soy, and dairy, using a minimal hypoallergenic capsule (hypromellose).
Evidence & Testing
Thorne is a frequent collaborator with the Mayo Clinic and NIH for clinical trials. This specific product is NSF Certified for Sport, the highest tier of third-party verification in the industry.
Brand Transparency
Thorne operates an A-rated TGA-certified manufacturing facility. They provide detailed sourcing information and conduct four rounds of testing for every batch.
Value Assessment
At roughly $0.17 per serving, it is a premium-priced supplement. However, the cost is justified for athletes or those with severe sensitivities requiring guaranteed purity.
Why Not Alternatives?
Unlike mass-market brands like Nature's Bounty, Thorne avoids soybean oil and artificial preservatives. While more expensive than big-box brands, the NSF certification provides a level of safety and potency verification that most competitors lack.
More in Supplements & Vitamins
Thorne
Basic Nutrients 2/Day
NSF Certified for Sport. Uses bioavailable forms (methylfolate, methylcobalamin, chelated minerals). No unnecessary additives. Trusted by Mayo Clinic and Olympic teams.
Pure Encapsulations
O.N.E. Multivitamin
Hypoallergenic formula free of all common allergens. Metafolin (5-MTHF) for methylation. Sustained-release CoQ10. One capsule daily simplifies compliance.
Nordic Naturals
Ultimate Omega
IFOS 5-star certified for purity. Triglyceride form for 70% better absorption than ethyl ester. 1280mg EPA+DHA per serving. No fishy burps.
Carlson
Vitamin D3 2000 IU
USP verified for potency and purity. D3 (cholecalciferol) is the form your body makes from sun. Single ingredient with no fillers.