Your soil is extremely important for what vitamins the vegetables can actually produce.

For instance, if your soil is totally devoid of cobalt(from my memory it may be something else) the vegetables will not make B12.

Again from my memory so it may be someone else but Geoff Lawton talked about this when he was feeding his family 100% from their own garden/food forest.

One of his sons actually got sick from vitamin and mineral deficiency because his soil was low in certain minerals. This was over a long period of time.

There are various things you can add to the soil, diluted seawater(there is actually a method to remove the salt and create a concentrate but I'd have to look it up I can't remember the exact details.)

Molasses is also full of minerals and it's awesome food for the microorganisms that help the plants uptake nutrients.

Rock dust, usually it's crushed basalt, there are various different kinds.

Seaweed extracts(seaweed grows in the ocean and the ocean has no shortage of dissolved minerals)

To learn more look up biodynamic soil amendments and that will take you down a rabbit hole.