There is obviously a fundamental assumption that vitamins = healthy immune system.
There are many other factors at play.
For starters, in which season do you have the most problems? Is it winter? Do you dress appropriately IE Scarves, enough layers, not sleeping with a window open in the bedroom...
How is your overall health? Do you have other concerns such as fatigue, frequent loose stools (diarrhea), poor appetite?
Do you over exert yourself on a regular basis through exercise or daily work (for income).
Are you chronically stressed?
Stress produces stress hormones which actually insert themselves into the cell walls of immune and other cells to signal the DNA of that cell to stop producing immune response signalling substances .. These hormones can remain in the cell wall for significant time periods after the event or stressor...
I was taught to that vitamins help my body.
Yes, Winter, but Autumn plays a role too..
Yes, I dress more for those seasons to not get a bladder infection (I used to get them very often, kidney and bladder issues) or overall not get a flu, but it happens no matter what I do (Not trying to think negative, just saying how it is).
My appetite is weird some days and the other days it's all good. What I mean by that is that some days I only feel like eating lunch and that is it, no more food, the other days I eat breakfast, lunch and dinner and I get way more hungrier that I have to eat some more.
I had diarrhea last week quite a lot, it started with my lower part of my tummy (not whole) started to hurt quite a lot.
I actually do exert myself a lot, especially since this is my last year of high school, but my sudden terrible health is making me lose school time (where I study for an important exam in one important class).
I usually stress a lot in school, rarely at home anymore.
Oh, I see, I never knew that... Thank you for explaining me this.