Vitamins & Minerals

Fortification fails for two reasons, and neither is the vitamin itself. The first is that the nutrient is destroyed during processing — heat, oxygen, light and moisture are all relevant, and the stability of each vitamin against each differs considerably. The second is that the nutrient is not bioavailable. A label claim measures what was added, not what the body receives, and the two can diverge substantially depending on the chemical form chosen. Chemical form is the decision that most often gets made by accident. Vitamin D exists as D2 and D3, with different sources and different regulatory positions. Vitamin C exists as ascorbic acid and as several esterified and buffered forms with materially different stabilities. Calcium can be supplied as an inorganic salt or as a chelate, with a large difference in absorption. If you are claiming a nutrient content at end of shelf life rather than at time of manufacture, overage becomes a necessity. The size of that overage depends on the process severity and the vitamin involved, and it should be calculated from stability data rather than estimated.

What a certificate of analysis does and does not establish

A certificate of analysis establishes what was measured in a specific sample, using a specific method, on a specific date. It does not establish what will be present at the end of your product's shelf life after your process has acted on it. That second question is answered by stability data for the vitamin in a matrix resembling yours, or by overage calculated against a validated processing loss.

Where a nutrient is added for a label claim rather than for function, the relevant number is the one measured at end of shelf life. Ask for the method and the date on any analysis you receive, and if the method is not the one your customer books value against, say so before the sample is approved.