non-GMO products with citric acid and the like

Most corn is GMO, so if an ingredient is usually derived from corn (like citric acid), when the product is certified as non-GMO, my understanding is that those ingredients are then usually sourced from non-GMO certified products from the UK or Europe (where non-GMO is cheaper than in the US due to their regulations), which are usually wheat, and that there is no requirement to state any of this on the label. Does this impact k for p status of non-GMO products?

Potentially. We are more careful with products not from the US