A while my mom threw some expired vitamins in with one of her plants and it seemed to explode in healthy growth! I tried it another time and it seemed to have no effect. Maybe it depends on the plant or vitamin?
I used one a day men's. DOn't know what she used. Probably not a men's multi vitamin though lol.
Another thought, she put it in with a flower, not a veggie. I used it on a veggie.
USDA Zone 7a, Sunset Zone 32.
Failure is only a fact when you give up.