Bioaccessibility of vitamin A, vitamin C and folic acid from dietary supplements, fortified food and infant formula.

In the Netherlands, vitamin intake occurs mainly via food and for some vitamins also via fortified food. In addition, some people take dietary supplements. Information on the bioavailability of vitamins is important for a good estimation of the actual exposure to vitamins. Furthermore, for a reliable intake estimation, it is important to know the accurateness of the claimed vitamin concentration on the product label. In the current study, the amount of vitamin A, vitamin C, and folic acid in different products and their maximum bioavailability (bioaccessibility) were investigated. In about half of the products, the amount of vitamins significantly deviated from the declared amounts. The vitamin bioaccessibility ranged from <1% to 100%. When assessing the dietary intake exposure of vitamins, it is important to take into account both the possible deviation from the declared level and (the variability of) the bioaccessibility of the vitamin in the products.