Just imagine, those who will be sent to colonize Mars will be among the most admired explorers ever, and they will all be vegans! At least they will be once they get there, so they should start getting used to it now.
What will they, or should they, eat for breakfast to stay healthy and enjoy themselves? Imagine that you have been chosen to be among the first group to colonize Mars, and you have used up all the supplies that were sent there in advance. Now you are on your own to produce your own food. What would you hope to have for breakfast? Would lunch and dinner be the same?
Important points to remember:
*Being that vitamin B12 comes from animal protein, where will they get B12?
*Iodine is needed for proper thyroid function and is mostly contained in seafood and plants grown in iodine rich soil. How will they get enough iodine?
*Zinc comes mostly from animal sources, legumes, nuts, seeds and grains. Will they have those sources on Mars?
*Vitamin D3 comes mostly from animal sources and exposure to the sun. Will they have that?