5mg of folic acid is the new recommended dose in North America - any thoughts?

[lerenardroux]

I'm a Brit living in N.America. I'm a conception board lurker! I've just found out I'm pregnant and have been taking the UK recommended dose of folic acid 400ug for months and months and months now.

I rang up the obs/gynae people here after my BFP to find out the next step etc. Was rather alarmed when they said I should be taking 5mg of folic acid daily, and is recommended for at least 3 months prior to conception. I'm perfectly healthy, no prior history of neural tube defects or miscarriage etc.

At the time I took that recommendation with a big pinch of salt. I thought it was the typical N.American approach to gung-ho dietary supplementation. I'm always happy to take NHS recommendations.

However, I've since spent a bit of time with Dr Google (I know, I know!) and it does seem that studies in the last few years have shown that 5mg daily gives a 90% reduction in risk of neural tube defects, whilst 400ug only gives a 47% reduction. The recommendations here are now for all women to be getting 5mg daily.

What do you reckon this? Is the NHS behind the times, or is the N.American system nuts?! It seems like the N.Americans have the science behind them…

Oh…and here's a link to the guidelines

Can you even get 5mg folic tablets over here?

That's interesting. I think you need a prescription to get 5mg. I don't know whether the nhs are behind the times - probably. The food industry here are because they don't fortify their flour with folic acid like they do in other countries. I don't know what the rates of spina bifida and other birth defects are in this country but I was reading just the other day that only 30% of women in the uk take folic acid before getting pregnant. So you have done more than most.

I was prescribed 5mg here on the NHS as if you have a higher BMI they want you to have the higher dose automatically.

Prior to conception, I was still taking 5mg a day, as I was aware of the research, and so wanted the higher level...

You can't get it on prescription at that level in the UK if you aren't pregnant, and you can't buy it in the shops, but my multi vit had 400mg, so I just supplemented this with 12 of the 400mg folic acid tablets you can buy over the counter per day, which took me over the 5mg threshold.

The 400mg tablets are absolutely tiny, you can swallow 12 at once with a bit of water easily, and they are hugely cheap, think mine were about 300 for £2 from Sainsburys.

The only drawback from the higher level is it can cause you bowels to be loose, particularly at first.

Those with a high BMI are more at risk from having a low level of folic acid, so I can see why the US are more careful at prescribing it to everyone, as they have more women with a high BMI, but the research does clearly show the higher dose is more protective, and so it seems the NHS have decided to concentrate their resources on the highest risk group and save money by risking it with the lower risk categories.

sorry all the 400mg should be 400ug! 13 x 400ug = 5.2mg!

Also, if you have been taking the 400 for months prior to conception, you would be starting off with a really good base level to begin with, so I wouldn't worry too much x

On NHS website I read 5mg is prescribed for pregnancies who may have high risk neural defects. This is if past pregnancies have been affected by it or in family history, partner has it or if one has diabetes.
Otherwise 4mg is enough alongside eating food that contains folic acid.
Hope that helps and good luck xxx:-)

I don't know about 5mg folic acid tablets, but 1mg tablets are for sale in every pharmacy over here for around $7 for 100. The obs/gynae person advised 2x 1mg in the morning and evening plus a maternal multivit that contains 1mg.

I've started the higher dose. I've decided to keep it up for the next few weeks at least over neural tube closure time (am just 5 weeks), then I'll prob go down to 400ug again after that. I weighed up the evidence and that's what I'm most comfortable with.

I feel bad to abandon the NHS advice. But it did always seemed a little strange to me that they advise the higher dose to women after they've had NTD issues. Bit late then really. 90% of spina bifida cases have had no prior issues. And as armadale says the 400ug may not cover those with a higher BMI, and as devonloch says there is a compliancy issue which 5mg daily may help to provide cover for. Though if women aren't going to take 400ug, they aren't going to take 5mg either, are they?!

At the end of the day the odds of a NTD are very slim. But I thought it worth raising the point that 5mg may be more advisable. However, highly likely that more studies will come out in the next few years to contradict this!

In Australia the advice is to get 600mcg of folate from your diet plus take a Multivitamin with .5mg a day. So loads lower then either UK or US.

Hazchem…that would make 1.1mg (1100mcg) daily, so almost 3 times the standard UK advice.

I think the UK advice is only about the supplemental level. I haven';t seen how much to include in your diet.

I wonder if the US advice is actually .5mg not 5mg as that is a huge difference. (i base this on evidence. Just wondered why the amounts would be so hugely different. as .5mg is 500mcg and 5mg is 5000mcg which sound huge.

The N.American advice is 5mg.

Yes, it is a huge difference…I thought I was mistaken initially but no the advice here is definitely for 5mg daily.

There is a wide range advised worldwide:

400mcg UK
1100mcg Australia
5000mcg N.America

I've become quite interested in this because of this disparity in advice and I've done a fair amount of reading. When you read the studies, as opposed to health service advice, the evidence is in favour of 5mg daily dosing for all women trying to conceive or that are pregnant.

I don't advocate popping pills just on the basis of what N.America is saying. But I would suggest folk to have a read for themselves, as the NHS may be behind on this one, especially as the UK doesn't fortify flour/grains like other countries.

Does anyone know if there are any issues with taking a large dose of folic acid (like there would be with vitamin A for example, not that you'd be taking that in pregnancy), or is it like vit c, with any excess excreted in urine?

Never mind; have googled and it looks like it is water soluble. Huh, this is interesting advice then (well, it would have been anyway). I'm past the point where I need to take folic acid, but if I was earlier in my pregnancy... Hmm.

This is surprising reading for me too - and I'm in N.America!

I am a Brit living in the US, and I have recently been having appointments with a fertility clinic here, with a view to having IVF in the near future. In my initial consult my doctor asked me if I was taking any vitamins or supplements. I said yes and produced the bottle of prenatal vitamins I have been taking so he could see for himself exactly what I was having.

He said it was a good start, with the 800mcg of folic acid it provided, but he advised that I consider buying some folic acid separately and take in another 800mcg daily from that. It is pretty cheap stuff - I got 350 400mcg pills for $4.50 from my local grocery store - so well worth doing IMO.

So I have been taking 1600mcg for the last month and feeling like I was taking loads compared to UK guidelines! Might add another pill or two to my routine now though, as folic acid doesn't seem to be something you can take too much of. Cheers OP.

Regarding risks of overdosing…

as Aliama says it's water-soluble so doesn't accumulate in the body.

There are concerns that high folic doses can mask B12 deficiency and the anaemia associated with it. This is what it says on a lot of government health websites, including the NHS site. However, this has been disproved by recent studies.

There is mixed evidence of a link between cancers and high-dose supplementation. The studies showing a cancer-link are not related to short term supplementation through pregnancy. I guess for those whose TTC journey takes longer than expected whilst on high doses should read the evidence for themselves and confirm with their doctors. I was TTC for quite a while and I don't know if I'd have been wanting to take 5mg over that period of time.

I'll be meeting my obs/gynae doctor for an early scan in 2 weeks. I'll update if she says anything of note that hasn't already been covered here.