Pernicious Anaemia Society
14,170 members10,155 posts

B12, hormones and the menopause

Really looking for experience of others and probably not just the menopause

On 27th August my last period started - it still hadn't stopped ... in fact it still hadn't really happened by 8th September meaning that I usually have one light day, one-two heavy days and then some spotting ... where as I'd have about 5 light days followed by continuous spotting - not enough to make me think anaemia was a problem - in fact quite the opposite as bleed would probably have been heavier if I was anaemic. Anyway, I was feeling very drawn and was a bit concerned that something else might be going on in the womb (at back of mind as mum has recently been diagnosed with cancer of the womb after an unexplained bleed - but she was well past menopause so thought it unlikely as I wasn't the right age for that particular form of cancer ... but nevertheless it was at the back of the mind).

So went to see doctor yesterday - gave me a pelvic exam which was useful as it didn't show up anything untoward so made menopause most likely explanation for the extended bleed. As I was feeling drawn really didn't want to just leave it another couple of weeks so accepted the alternative of some 'progesterone' type hormone to put me back in a different part of the menstral cycle - noresthisterone ... which having looked at today has some suspected interactions with lowering B12, but that is another story. Thought as I was cycling back that I was probably going to have migraine - which I did - but wasn't expecting to have hot-flush, and feel so damned awful today - nauseus and head/migraine that needed a lot more treatment than normal (use a triptan but at very low doses). Also been more difficult to move and I've been wheezing a bit/stuggling for breath.

I had my NHS maintenance shot at lunch time and felt even more dreadful after that ... and had several incidents of just standing there being unable to move this afternoon - when I was trying to play a game of bowls - got kicked up the backside by a friend because I couldn't move away from the mat and was stopping them bowl :).

Anyway, decided to not have lunch time dosage - still feeling very warm but not as hot and head is a lot better.

Probably means going back to bleeding in a few days so need to figure out some way of managing that - which may mean trying cutting the tablets into fractions and seeing what that does (nothing like a bit of experimental medicine :))


a) wondering what others have experienced of B12 and the menopause

b) wondering what others have experienced in terms of norethisterone and other progesterone replacements.

c) wondering how generally people find changes in hormone levels affect their need for/reaction to B12.

I have this theory that hormones really impact on how my body uses B12 and just wanted to know what experiences others have ... though I don't think that is just related to the menopause.

11 Replies

I can't really comment on a lot of what you ask except that I am in the menopause and have B12 deficiency. The first few years of menopause are the worst for some of us. It was hell for me but I rode it out without hormonal help. It sounds like you might lead a 'sporty' kind of life (?) where you burn a lot of energy. I'm not sure if this is a well-known fact about B12 or not, but if you are on B12 supplements, any kind of exercise burns up your B12 stores. Illness also burns up more of it, although whether a doctor would believe this or not is a moot point! Ergo, you often wonder why you feel like awful until the penny drops. My B12 levels were just coming up to par in July when I did a lot of vigorous exercise. It's been downhill since then. Best of luck! :)


It is well known in the sporting fraternity that you burn a lot more B12 if you are active - less so in the medical. Bowls not really a particularly sporty activity but I also jog and cycle a bit though hadn't felt like it at all in the day after taking the hormone - really had totally knocked me out - think that it probably did something to the way my body processes B12 as the reaction after the maintenance shot was extremely weird for me.

I get through a lot of B12 and before I started supplementing I was probably showing more menopausal signs - periods were heavier and less regular and the anxiety prior to period was unbelievable ... which all went when I got the levels right.

Feeling much better today - temperature back to normal ... still feeling a bit tearful in the background but not as bad as it was yesterday so definitely don't want to be taking that dose again!


That does seem a long time ! I know little about the connection with B12 and Menopause - however it is the time of life when the thyroid has to work overtime in order to balance the hormones. Puberty - pregnancy - are the other times that is very challenging for the thyroid as I am sure you know. As you have the B12 under control I am wondering if you have had any recent test results for the thyroid - in particular the FT3 - as that is the active hormone - also the most important one and rarely tested by GP's/labs - Costs ?

I was way past menopause before my B12D and Thyroid were diagnosed and sorted although I did suffer with fibroids. Stayed well away from Docs just in case they wanted to do a hysterectomy :-(


Hi Gambit!

I'm sorry you are feeling crook!

A few years ago I started getting serious migraines occurring with my periods (they were lasting up to 3+ weeks & 1 hospitalised me) so I was put on the progesterone only pill (Desogestrel) so I didn't get periods and therefore no (very few) migraines. It's since then that my B12d has got a lot worse.

I think it's probably coincidence and just a result of having had it for 20 years already, getting older & huge amounts of life stress but there may be a link.

I wouldn't stop the POP though: no periods suits me well and the migraines were worse than the B12d as nothing would help & they were even more debilitating for 75% of my life.

I'm not sure if this helps you, sorry.

I hope you feel better soon.

Best wishes, D


Glad that the pill worked with your migraines - mine are also related to hormones but both sets of changes trigger them - not common I think but also not unusual and something I think GPs probably aren't very aware of. I was put on pill at one point but it was a disaster as hormones were continually being changed so did absolutely nothing for migraines and caused a prolonged small bleed and just left me feeling totally out of it - so obviously something that doesn't work for me.

1 like

End of December 2010 was my last period. It was the mother of all periods, heavy bleeding lasting 2 weeks (later found out I had fibroids). When I finally got in to see my doctor, he said if it happens again to come in when it starts (but never had one again). I'm pretty sure my pernicious anemia had started by then as a couple months before I had the worst stomach problems ever, but could not figure out the cause. Doctor tried me on Prilosec (omeprazole) but I could not tolerate the side effects (weird crawling pains in my upper back).

I had a lot of hormonal ups and downs for a couple years before and after that time but my traditional doctors only tested TSH, never did a B12 or hormone testing. Somehow I got through that time. I now believe some of my symptoms I attributed to hormonal changes were likely B12 deficiency creeping up (night sweats, insomnia, afternoon fatigue, irritability). Menopausal changes can be confused with some B12 deficiency symptoms. It wasn't until 4-1/2 years later I was diagnosed with B12D and PA.


Yes GP said that this might possibly be the last period - and may be it will be. Mind you she also said that at 53 I was a bit old to have not started the menopause ... do GPS really not know what an average is!!!

What was interesting for me was the extent to which just a hormone seemed to be knocking my B12 levels for six. Feel much better today - 24 hours since last tablet so definitely thinking it was a progesterone OD for me so if I need the tablets again certianly won't be looking to taking whole tablets.


Hiya Gambit.. Sorry to hear that you've been suffering, before I was diagnosed with B12 nearly 3years ago my periods stopped for 5 months feeling really ill the doctor assumed I was going through an early menopause,(I had just turned 40) So I had lots of bloods done various tests when the results came back I was then told I had B12 and folate deficiency.( which a little later I found out I've had It for coming up to 18 years undiagnosed) the doctor then explained that my B12 & folate def were the cause of my periods stopping and that the folic acid and B12 shots would help nature take its course..

Which I'm happy to say the doctor was right for a change. Hope you feel better very soon☺️


Feel fine today. Obviously just didn't need that large a dose of progesterone subsititute :)


I'm in the menopause and have b12 d. You don't give your age. Have you had your thyroid checked. Hypothyroidism will cause the bleeding you're describing. A natural remedy for womb trouble is cayenne capsules. I understand the problem with taking hormones I am also allergic to them.


The one day seems to have done the trick though I am aware that the bleed may well come back in a few days time.

I'm 53 so in the age range for the menopause ... and think it is consistent with other members of the family.

I did have problems with bleed when I tried the mini-pill for migraines (really didn't work as migraines triggered by both changes in hormones and the levels were just see-sawing all over the place).

If I need to go back then I'll ask about the thyroid ... though there really isn't a family history at all.

Symptoms for so many things overlap so much.

1 like

You may also like...