Inspired from this question about macronutrients, here I propose the analogue for micronutrients: are vegetarian and vegan micronutrient needs the same as traditional diets?
Does any factor in vegan or vegetarian diets (nutrient density, fiber amount, gut microbiota, nutrients interactions, etc.) influence the micronutrient requirements?
The matter is vast, so it's difficult to give a complete answer. I start a community wiki and I hope more participants to improve my answer.
Iron requirements
The American Dietetic Association's "Position on vegetarian diets" suggests to increase iron consumption:
Because of lower bioavailability of iron from a vegetarian diet, the recommended iron intakes for vegetarians are 1.8 times those of nonvegetarians.
Omega-3 requirements
There's already a good post on this subject, that can be synthetized as:
Scientific research shows Omega 3 is not a major concern neither for vegetarians nor vegans, since clinical trials show that omnivorous, vegetarians and vegans showe similar blood levels of Omega-3s. This could be due to increased capability to convert ALA into EPA and DHA. If intervention studies were to confirm these findings, it could have implications for omega-3 requirements.
Whole products and phytic acid
Phytic acid, present in whole meal products, can inhibit absorption of several minerals, such as zinc, iron and calcium, and possibly also magnesium and copper. However sourdough fermentation can prevent phytic acid to cause this decreased absorption. (Lopez 2002)
