I have had glaucoma for over 10 years- I’m 40 years of age.
I read about b3 being part of a trial and showed some positive results so I thought I’d give it a go.
This is my story:
I started taking 500mg nicotinamide in February 2022 (1 a day).
By spring 23’ I noticed I was struggling to fully empty my bladder in the evening (it may have started earlier but it wasn’t something I paid attention on).
In august 23’ I upped the nicotinamide dosage to 3000mg per day, taking 6 capsules throughout the day.
after two weeks I noticed that I was having urges to pass urine a little more frequently, however, soon after I went into urine retention, I hadn’t passed urine for over 30 hrs and had to have a catheter fitted.
bloods/scans all came back fine.
The doctors at moorfields, the vitamin manufacturer have never heard of a reaction like this.
anyone else experienced a bad reaction? My advice, if you take this for glaucoma, simply, DONT!
Just to continue:
As the doctors couldn’t find any link, after a month or so,I restarted taking nicotinamide, 3000mg however I was more accurate on the timing. Again, after two weeks, I noticed an urge to pass urine, that was followed by great difficulty in passing urine at all, which lasted for 6/8 weeks- while I didn’t go into full retention, every time i went, I had to strain sitting. Even with my bladder feeling almost empty I still felt I needed to go. It was horrendous.
I stopped taking nicotinamide for over a month, and in February this year, restarted, taking a dosage of 500mg-1000mg a day- after only four days, noticed an urge to pee even after I had done so, for a further 2 weeks, difficulty passing urine.
don’t know if it’s to do with the effect of the bladder, or the effect it has on the brain. But clearly, it doesn’t suit everybody.
Written by
Blindbeggar83
To view profiles and participate in discussions please or .
Hello, I was diagnosed with normal presssure glaucoma in 2003 like you I heard of the vitamin B3 trials from February- December 2023 I took one 500mg B3 (Nicotinamide) daily. I have neuropathy ( nerve pain) was on 125mg Pregabalin daily for two years, on 3rd November 2023 changed to 300mg Gabapentin daily, by January 2024 I had a rash which developed into large blisters. February diagnosed with a rare skin desease Bullous Pemphigoid.
Dermatologist first suspected change of medication cause of blisters, now saying Gabapentin does not cause such a strong reaction.
Hi. I've been taking B3 for about year with no side effects. Having been diagnosed in 2017, suddenly, in between hospital check ups, I suffered damage to the optic nerve in my right eye. Ultimately, I lost most of the sight in my right eye. I've now had trabeculectomies in both eyes, and pressure is under control. My left eye has good vision.
I've weighed up the risks of taking B3. I was lucky enough to speak to Prof Sir Peng Khaw at Moorfields during a research open day last year, and I've also "attended" a Glaucoma UK webinar about B3. I think the evidence so far points to a very low risk of complications if you take 2000mg per day. I've been told taking 3000mg per days carries a slightly higher risk of kidney function issues, and to have your kidney function checked if taking 3000mg. For this reason I reduced my intake to 2000mg per day as a precaution. It sounds to me like you've been very unlucky to have side effects, or maybe the symptoms were unconnected, but if you're concerned there's a connection I completely understand why you'd stop taking it. I guess my point is that everyone taking B3 should make an informed decision - there my be risks, but from what is currently known they're low risks. In my case, I'm happy to take those risks, if it could help preserve the sight in my left eye.
My consultant at Moorfields, Deborah Kamal, recommended 1000mg per day, so I take 2 x 500mg. Did the Prof recommend 2000mg per day? I don't think I'd dare take that much.
When I spoke to the Prof, he said the risks were thought to be very low. I can't remember if he explicitly said an amount, but I think I told him I was taking 3000mg at the time and I don't recall him saying I shouldn't. Like I say though, I subsequently took part in the Glaucoma UK B3 webinar, and the consultant that hosted that recommended not exceeding 2000mg unless you could get your kidney function checked - so I dropped to 2000mg then. I've not had any side-effects. Maybe you should discuss it with your consultant at your next appointment? For me personally, having little sight left in my right eye, I feel it's a risk worth taking if it could help preserve the sight in my left.
Hi there. Thank you for sharing your experience with taking Vitamin B3 (nicotinamide). Some ophthalmologists have told us in the past that it can have some side effects at high dosages, which should go away if you stop using it. We always recommend to speak to your eye specialist if you are going to try any new supplement, so they can monitor your progress and also advise on dosages.
Hi! I have been taking Vit B3 nicotinamide for over 10 months now, increasing the dose to 3g daily within the first 4 weeks. Taking 3 tablets with lunch and 3 tablets with dinner. I put myself fwd every 6 months to my doctor for a full blood test including liver function and so far with the doseage and the blood tests I have no adverse effects. My cholesterol LDL has reduced and I also monitor my saturated fats intake daily which has helped me lose over 20lbs in weight over the period. I am praying that the VitB3 trial is successful as feel its my only hope. I am already blind in my right eye since 1998 due to an operation for an aneurism so I am left with my left/lazy eye which has glaucoma-the brinzolamide and ganfort don't seem to be reducing the pressures which sit around 14..I lost my driving licence 6 months ago due to a failed VF TEST.. I am classed as high risk for trab etc operations. My life seems to have been taken over with almost daily research to find what else I can do to keep my remaining sight-the VF TEST picture shows most of the top half of my eye is shaded black...so its fingers crossed for VitB3 to keep deteriation at bay..I also take supps C0Q10 VitE Ginko Biloba cod liver oil (for years!) Omega 3..
I'm sorry to hear of your troubles taking b3 and I hope they get sorted out for you soon.
As others have said, we don't all recat the same to medication/supplements and it is a matter of making a personal, informed choice.
I saw my Consultant Ophthalmologist (who is an eminent glaucoma Professor) just last week as I have been having some trouble in keeping the pressure in my right eye low enough. Amongst other things, he advised me to start taking 1g of Nicotinamide a day and having looked at the pros and cons, I will be doing so. As I am also a long time user of Diamox, which also has diuretic effects, I already have my kidney and liver function monitored. I will keep my fingers crossed that I don't get any urinary prob;ems with the Nicotinamide.
Please find information received from Professor David Garway-Heath who is part of the trials.
If a patient’s glaucoma is stable and well maintained, there is no real need to discuss B3 with them as their vision is not being threatened.
B3 is normally discussed with patient whose glaucoma has worsened, despite treatment. Also, this may be discussed with patients after surgery if the results were not as successful as hoped. These are the patients that he would discuss B3 with. He always makes sure they are aware that currently there is no evidence in humans that B3 is helpful, which is why they are doing the trial.
However, the trial shows that there is good reason to believe that it will be helpful and there are few potential side-effects. If the patients decide to try it, then he has no objection in them doing so, which seems to be how your consultant feels.
The recommended dose is 750mg twice a day with food for 6 weeks, increasing to 1.5g twice a day (or a lower dose if this is not tolerated) with food thereafter.
I’m quite confused by the suggestion that there are a few potential side-effects of taking high doses of B3. Internet search shows that high doses can cause increases in histamine, skin, flushing and itching. This is something I would be keen to avoid. Does this brand avoid such side-effects?
I tried it as well - 6 tablets to start with. Wanted to pee all the time so stopped it for a while. I've carried on taking just one 500mg tablet a day. I've always had what I call a sensitive bladder so I don't notice the difference with only taking one.
Fortunately/unfortunately I can pass urine all the time, even 10 minutes after the first time. I'm never sure whether I need to go or whether it's just a feeling
In my experience always read the blurb about side-effects in the small print leaflet you get with your medications. I say that because doctors don't always connect symptoms to medication. Not even at consultant level.
one thing, really important I forgot to mention and wondered if anyone else experienced this,
The two times I’ve taken nicotinamide for two weeks at 3000mg a day, each time when I’ve had problems passing urine, I’ve also experienced a really unusual metal/salty taste coming from my gums which lasts for weeks after
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.
Right eye impacted by left eye
DVLA not getting anywhere advice needed
Help recommendations needed on eye droppers 
Does the Trab need much aftercare?
Drops and travelling rant…😣
