Full blood count

[Molly161018]

I've got a full blood count teat next week, should I fast for this, and presume I should cut out b vits and iron supplements for a week before?

MT in advance

[SeasideSusie Remembering]

Molly161018

A full blood count measures red and white blood cells and platelets.

Sometimes when an FBC is ordered then certain other tests might be added as default, or might be added and the patient not told about them, eg liver function test, kidney function, Us and Es, etc.

Iron is not included as part of an FBC.

I think you have two choices here.

1) Ring the surgery and ask exactly what is being tested.

2) Assume they may add something that requires leaving off certain supplements so leave everything off just to be sure.

Biotin, which is in a B Complex, needs to be left off for 3-7 days before any blood test as it can cause false results. So if you take a B Complex that usually contains a small amount of biotin (possibly around 400mcg) so 3-4 days is likely to be enough. Biotin as a stand alone supplement or in a hair/nail supplement is often much larger dose, eg 5mg or 10mg and that needs to be left off for a week.

Iron needs to be left off for a week if any iron tests are included.

Other supplements can be taken up to and including the day before the test.

[Molly161018 in reply to SeasideSusie]

Thanks Susie, thats helpful. I think I'll just assume they might include some other tests otherwise I'll be waiting for half an hour on the phone to find out for sure!!

[SeasideSusie Remembering in reply to Molly161018]

I think I'll just assume they might include some other tests

This is what I do for pre-arranged tests so I always book an early appointment and don't have breakfast before I go and not take my thyroid meds. I always ask exactly what they're testing and if I have taken my thyroid meds and they say they're including thyroid test then I refuse it and say I'll come back for that another time.

[Molly161018 in reply to SeasideSusie]

yes mine is 10am so I should survive without breakfast!! Better safe than sorry I think!