To add to this, you really need a blood test to show what you need. Some docs will talk out their ass about dieting (this is rare, but it happens). Always get bloodwork to confirm.
Also, some vitamins are water soluble, others need to be taken with food. Your doc should know though
I’m a vegetarian and people assume I need B12, but my bloodwork shows I’m fine. I did need some D though, since apparently hiding inside for 3 years during a pandemic can impact your body… who would’ve guessed??