High white blood cells

I got my bloods checked in June 2022 and my white blood cells were sitting at 13.2 when the average range is between 4-10 I’m sure? The doctor didn’t seem too worried and said we would test again in 3-6 months.

I got them checked again 2 weeks ago and they went down to 12.9, still high but their getting lower. The doctor said I also tested low for iron and folic acid, which I’ve started taking medication for.

Does anyone know of any ways I can lower them?

Food? Supplement? The doctor doesn’t seem too worried but said if their still high in my next blood test, their referring me to a specialist to look into this more.

Has anyone else’s levels been slightly high?

I also tested positive for Covid in September and currently have costochondritis which I’m taking ibuprofen for. The doctor thinks Covid caused this.