My wife has gotten big into juiching (begetables and fruit) to get extra vitamins and nutients in.
Now, juicing might not be doable in a shtf situation, but we also started growing out own wheatgrass, which gives you lots of vitamins and nutrients. Its easy to grow indoors and you dont need a lot of it everyday (about 20 ml per person each day). Instead of juicing you can.just chew on the grass and spit the pulp out.
Would that be helpful when food might be scarce?
Besides growing wheatgrass, the seeds can be made into flour for bread, pancakes, etc.