Asking for a friend. When having a full iron panel. When is it best to stop supplementing?

My friend is having a full iron panel and had been taking an iron and vit c combined supplement. When is it best to stop taking it before the test and does it matter what time of day the test is done?

Thanks in advance 😊

[SeasideSusie Remembering]

Leave off iron supplement for 7 days.

According to the NHS a 12 hour fast (water only to drink) is required for iron tests so to avoid having to go without food for too long then book appointment as early as possible in the morning and fast from evening meal the night before.

nhs.uk/common-health-questi...

Common fasting blood tests

•an iron blood test (used to diagnose conditions such as iron deficiency anaemia) – you fast for 12 hours before the test

[Hidden in reply to SeasideSusie]

Thanks very much for the helpful reply. She just wasn't sure if the test could be done any time of day. So will book the earliest appointment 😊