Stop taking vitamins before blood tests?

[frizzfrazz]

Hello! I'm new here. I've not been diagnosed, but I have many, many symptoms, so going to ask GP to investigate. I may have had thyroid tests done before as part of routine blood tests, so will ask for previous results when I go.

I was wondering if I should stop taking vitamins before having blood tests done? (To show my body's natural state...? Sorry, completely new to this.)

I've been taking Vit D 25ug and Boots Rebalance Vit B complex for years as I feel they give me a bit more energy. I also take Vit C, but that's it. The Vit B complex has 100% NRV of: Thiamin 1.1mg, Riboflavin 1.4mg, Niacin 16mg NE, Vitamin B6 1.4mg, Folic Acid 200ug, Vitamin B12 2.5ug, Biotin 50ug, Pantothenic Acid 6mg

I've had low vitamin D, folic acid and iron a couple of times in the recent past (even while on these vitamins).

Should I stop taking the Vit D and Vit B vitamins this time? And how long before blood tests should I do this?

Thank you for your help & advice in advance - I really appreciate it!!

[SeasideSusie Remembering]

frizzfrazz

Which blood tests are you having done?

Leave off the B Complex for 3-5 days as it contains Biotin. If Biotin is used in the testing procedure it will skew results if you continue to take Biotin as a supplement.

[By the way, there are much better B Complex supplements available. Yours contains folic acid and cyanocobalamin, both are the wrong forms of the vitamins and it's recommended to take methylfolate and methylcobalamin. Most high street and supermarket own brands contain the cheapest and least absorbable forms of ingredients, often with low levels and lots of unnecessary excipients.]

No need to leave off anything else unless testing those vitamins specifically, just take them after the blood draw.

I've had low vitamin D, folic acid and iron a couple of times in the recent past (even while on these vitamins).

That suggests that you're not supplementing at the right dose, or you have naff supplements. We'll only improve our levels if we take the appropriate dose based on our results.

What is your Vit D level? 25mcg = 1000iu and is only suitable for a maintenance dose for an already good level.

[SlowDragon Administrator]

Ask GP for full Thyroid testing. That's TSH, FT4, FT3 and both TPO and TG thyroid antibodies

Important to test vitamin D, folate, ferritin and B12

Consider asking for coeliac blood test too

All thyroid blood tests should ideally be done as early as possible in morning and fasting. This gives highest TSH and most consistent results. (Patient to patient tip, best not mentioned to GP or phlebotomist)

If antibodies are high this is Hashimoto's, (also known by medics here in UK more commonly as autoimmune thyroid disease).

About 90% of all hypothyroidism in Uk is due to Hashimoto's.

Low vitamins are especially common with Hashimoto's. Food intolerances are very common too, especially gluten. So it's important to get TPO and TG thyroid antibodies tested at least once .

Link about thyroid blood tests

thyroiduk.org/tuk/testing/t...

Link about antibodies and Hashimoto's

thyroiduk.org.uk/tuk/about_...

thyroiduk.org.uk/tuk/about_...

List of hypothyroid symptoms

thyroiduk.org.uk/tuk/about_...

[Mary-intussuception]

I would make sure to ask for the Thyroid Antibodies to be tested : TPO (Thyroid Peroxidase ) and Tg (Thyroglobulin ). Write out full list of all symptoms. If your doctor asks why you want these tests just say (produce list) " as I have many symptoms of an Underactive Thyroid I would like to eliminate Autoimmune Thyroiditis ".

Ask for FreeT3 to be tested also as well as TSH & FreeT4.

With Hashimoto's Autoimmune Thyroiditis the regular Thyroid Function blood tests results can fluctuate and fall within 'normal " range. Mine did.

Do you sometimes have a low body temperature? Check it first thing am.

A the best.

[humanbean]

You don't mention iron, but if you ever take iron and want to test it, leave a gap of 5 - 7 days between last dose of iron and the blood test.

[Gambit62]

Biotin can interfere with a number of tests so you should definitely stop taking that - not sure for how long though - at least a week I would think and possibly more

[frizzfrazz]

Thanks so much everyone for your fast & detailed responses! I'm just at the start of all this, despite symptoms of at least 8 years and a diagnosis of 'chronic pain'. It just got to a point where it was another weird symptom and what's the point in reporting due to numerous previous tests and referrals not finding anything. Thank you SlowDragon I actually came here via Thyroid UK - it's a fantastic resource. I was surprised at how many of the symptoms I had on the list - really helpful as I've printed it out. Luckily my GP is great, so I'm hopeful about his being thorough with this investigation. Thanks again for all your help.

[SlowDragon Administrator in reply to frizzfrazz]

If GP can't or won't test everything, then get missing tests privately

You may need to get both TPO and TG antibodies tested and if you need to FT3 tested, you need to test TSH and FT4 at same time, not just FT3 on its own

[frizzfrazz in reply to SlowDragon]

Thank you! Good to know. Had appointment today. He's doing a big screen of vitamins, minerals & hormones and other stuff, but sounds like he is only doing TSH and T4 and will only do T3 if there's an abnormal result. Will discuss this with him in more detail when initial results are back as it was a big information dump of symptoms. He's been very understanding and helpful over the years, so expecting he'll do everything that he's able to. Will definitely look at private tests too.

[SlowDragon Administrator in reply to frizzfrazz]

NHS budget cuts means they will only test FT3 if TSH and FT4 are outside normal range