Vitamin D-3 1,500 IU

Vitamin D-3 is dosed in micrograms and measured in international units, which makes it unusually easy to get wrong. It also degrades with heat and light, so a tablet that met specification at blending can fall short by the time it is bottled. We assay potency on the finished tablet rather than on the raw oil. Every lot has to confirm 1,500 IU of cholecalciferol per tablet, tested after compression and packaging. Vitamin D-3 is fat soluble and accumulates in the body, which is precisely why the number on the panel has to be the number in the tablet.

Every Lot, Before Release

What We Test For

Identity testing confirms the vitamin D present is cholecalciferol, the D-3 form, rather than ergocalciferol. Potency is quantified by high performance liquid chromatography on the finished tablet to verify 1,500 IU per serving. Tablet weight uniformity is measured across the lot so every tablet carries the same dose. Disintegration testing confirms the tablet breaks down for absorption. Heavy metals are screened by ICP-MS for lead, arsenic, cadmium and mercury. Microbiological testing covers total plate count, yeast and mold, E. coli, Salmonella and Staphylococcus aureus.

How to Check a Lot

Reading Your Certificate

A certificate of analysis is a one page summary of what an independent laboratory found in one specific lot. The lot number at the top matches the number printed on the base of your bottle, so you can confirm you are reading the right document. Each row lists a test, the specification it has to meet, and the result that was actually measured. Results appear as a numeric value, as Pass, or as Not Detected, which means the substance was below the laboratory's limit of detection. Heavy metal results are reported in parts per million and compared against the limit set for that ingredient class. If a single row falls outside specification the lot is rejected and no certificate is ever issued. Certificates are added to this page as each new lot clears testing.