Warning about vitamin B6

Vitamin B6 is often mentioned as help to be relieved from high histamine levels, due to it’s important role in the breakdown of histamine by DAO.

But I’d like to warn everybody, it is well-known that high dosages of vitamin B6 can lead to neurotoxicity, meaning that it kills of your nerves. What is less well-known is that even in lower dosages in can have detrimental effects on certain people. Which I experienced myself.  I started taking about 25 mg a day, within a view days my limbs would often get numb, just like you get a sleepy leg or arm every now and then, but this was worse. They’d fall asleep constantly whatever position I took, I started to get tired and dizzy. And before I knew it, I was laying in my bed trying to find a comfortable enough place not to be bothered by the constant tingling and sleepiness of my body, while trying to remain conscious. Didn’t really help that deadlines and exams were coming up.

Luckily for me, the effect didn’t last very long, as opposed to those people who get problems after taking high dosages  for a long time, but it was still very uncomfortable and highly disruptive of my life. During the time I was able to stay awake, I googled like crazy, trying to find out what was happening to me this time. I soon found out about the toxic effects of B6, and that it can also have nasty effects in lower dosages in certain people.  This can be due to a certain sensitivity in those people, but it can also come from a deficiency of other vitamin B’s and magnesium. Magnesium shouldn’t have been an issue, since I already supplement with magnesium. Maybe it was due to the lack of other vitamin’s, since well, I’ve stopped taking complete vitamins and complete vitamin b supplements. As these contain minerals and vitamins that can lead to a higher level of histamine and should be avoided in case of a histamine intolerance. Yes folic acid(B9), vitamin b12 and niacin(B3) I’m looking at you.

So instead I’ve started to eat more foods that contain high levels of vitamin B6, the daily dosage is only about 1 to 2 mg, and the melatonin I often take also contains a view mg, so does the energy drink I often indulge in. And yeah I know caffeine is bad, the weird chemicals in it are also bad. But I need my caffeine dose and sugar dose, and I just love to drink them. When I don’t drink too many too fast it doesn’t affect me all that much. Though coffee and green tea, which both contain caffeine can make me feel very sick.

So if you’ve started taking vitamin B6 and notice any side effects like numbness, dizziness and fatigue. Stop taking it!

What is histamine intolerance

When I was told about the histamine intolerance I suffered from, I didn’t believe it at first, I was afraid it was some bogus disease or some well we don’t know what’s wrong, so let’s just call it so and so. Just like former diagnosis I had gotten like irritable bowel syndrome and chronic fatigue syndrome.

But a histamine intolerance is a very real thing. And it’s quite clear what the cause of it is.


Histamine is an amino acid. A very small one even. One of the most well known functions of it is in the mediation of immunological responses. When harm is done to the body or intruders are noticed, histamine is released from specialized storage cells (mast cells) in the bloodstream to widen blood vessels and make their walls more permeable, so more blood and all handy things carried in the blood to fight of harm and intruders can go to the place of the disturbance.

Which is the reason a lot of the symptoms of histamine intolerance mimic allergic responses or real infections.  Mimic, since it isn’t an allergic response or a reaction to a threat at all.  Just a large amount of histamine can cause these responses.

The reason large amounts of histamine can build  up in the body

There are several reasons a large amount of histamine can come into existence in the human body and lead to annoying responses.

Histamine is not just active in the human body. It is also present in most other animal life, and even in plants. Which means that most of our foods contain histamine. So we consume histamine with almost everything we eat and drink. There are also certain substances that are able to aggravate the mast cells in which histamine is stored, so their contents get released  into the blood stream.

There are several enzymes that break down histamine. The main ones are histamine methyltransferase which mostly targets histamine within cells. And there is diamin oxidase (DAO) which is present in the walls of the bowels and within the bloodstream.

Most histamine intolerances are due to a lack of DAO. Ingested histamine is normally filtered within the walls of the bowels, so it doesn’t enter the bloodstream. And the histamine that has entered the bloodstream is filtered away with DAO as well. As the amount of DAO declines, the amount of free histamine in the body can grow rapidly, especially when foods high in histamine are eaten.

DOA can be low due to a genetic disorder. But the production of it can also be impaired when the bowels get damaged due to an infection but also different aggravations (antibiotics, crohn disease, gluten). A third reason the amount of DAO can be low is because it can be inactivated by several different substances, like certain medicines (morphine ) , but also alcohol impairs the working of it. Another reason a shortage of DAO can occur is when the components it is build out of aren’t present in large enough amounts, for example a shortage of copper and B6.

Since the levels of DAO can fluctuate with all these different reasons, the sensitivity to histamine can change depending on the circumstances. After a night of drinking I have to be much more careful with histamine rich foods. Stress can not only release histamine directly but also work against the working of DOA.

Since the response depends on the amount of histamine within the body, and this depends on it’s turn on the amount of DAO, the amount of histamine that can be taken before reactions occur is different for most people. And as most reactions only happen when a certain threshold is passed it will take a while for anyone to find out where that threshold is, and how certain things like stress affect this.

The amount of histamine in foods can also greatly vary, since the longer it is stored the more histamine is made by bacterial activity and other processes. That’s why certain foods like fish are okay if they are very fresh or never got defrosted. The same goes for any other food, like fruits and veggies.

Published in: on February 16, 2010 at 10:37 pm  Comments (23)  
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