Vitamin B12 And Folic Acid Reduce The Risk Of Blood Clots In The Brain

October 31, 2005

After Americans enriched their diet with folic acid in 1996, the frequency of blood clots in the brain was reduced by 15%. Now research shows that added supplementation of Vitamin B12 will markedly lower this risk even further.

Immediately, it sounds simple: People with high levels of the amino acid homocysteine in the blood have an increased risk of blood clots in the brain and in the heart. You also know that you can lower homocysteine with folic acid and, to a lesser extent, with B6 and B12 vitamins. When the Americans began to enrich cereal products with folic acid from 1996, both the average American’s homocysteine and the rate of blood clot in the brain decreased by about 15% in three years.

“The money fits”, and then the result is almost obvious in advance, if you want to conduct a lottery experiment, where every other participant gets folic acid, B6 and B12 vitamins. Of course, they get fewer blood clots in the brain.

But the reality is more varied. In Norway, such an experiment (NORVIT) was conducted with 3,750 patients who had just survived a blood clot in the heart. For 3.5 years, they were supplemented with either folic acid (0.8 mg), vitamin B6 (40 mg), both or blind tablets (placebo). Among those who only received folic acid, mortality decreased approx. 10%, but not statistically certain. But in the other two groups the death tolls were increased, not statistically certain either.

Perhaps it is too late to start taking supplements when you are already severely calcified. Or, as will appear, perhaps it was more decisive that the Norwegians “forgot” to give the participants vitamin B12.

An experiment has also been carried out in the USA (VISP). It was with people who had recovered from a blood clot in the brain, but had an increased risk of a new one. Admittedly, the Americans did not initially find any effect either. Supplementation of folic acid (2.5 mg), vitamin B6 (25 mg) and vitamin B12 (0.4 mg) did not reduce or improve mortality or risk of blood clots in the brain. Therefore, the experiment was simply stopped after two years. It was useless, they thought.

B12 is useful if it is absorbed
A close explanation could be the aforementioned enrichment of cereal products with folic acid. After all, the average homocysteine had already fallen by approx. 15% in the Americans. During the trial, it only dropped a further 2%.

But the Americans have since studied the numbers more closely. In doing so, they discovered one important source of error in particular: Many of the 3,680 elderly participants had reduced absorption of vitamin B12 from the gut and therefore had relatively little B12 in their blood (less than 250 pmol/l). This is often seen in the elderly, and it is now known that these elderly need supplements of at least 1,000 micrograms of vitamin B12 per day. But the participants had only received 400.

What would it look like if you now disregarded these participants and concentrated on those with normal B12 uptake? It was decided to investigate. At the same time, participants with reduced kidney function were disregarded, as they also respond sluggishly to these supplements. Finally, participants who were previously receiving medical treatment with B12 were naturally disregarded.

There remained 2,155 people who had no problems absorbing B12. In this large group, the supplements both lowered homocysteine further and reduced the overall risk of death, blood clot in the heart or blood clot in the brain – by 21%! The treatment helped anyway; even a lot when the ability to absorb B12 was intact.

As stated, it appears that the fortification of cereal products with folic acid has reduced the Americans’ risk of blood clots in the brain by approx. 15%. Now it seems that a solid supplement of vitamin B12 on top of that can reduce it significantly more – but the many elderly people, who absorb vitamin B12 poorly, presumably need larger supplements.

This is the result at the moment. It must be verified before it is approved. But the indications are there.

By: Vitality Council

1. Toole JF, et al. Lowering homocysteine in patients with ischemic stroke to prevent recurrent stroke, myocardial infarction, and death: the Vitamin Intervention for Stroke Prevention (VISP) randomized controlled trial. JAMA. 2004 Feb 4;291(5):565-75.
2. Bonaa KH. NORVIT: Randomized trial of homocysteine-lowering with B-vitamins for secondary prevention of cardiovascular disease after acute myocardial infarction. Program and Abstracts from the European Society of Cardiology Congress 2005; September 3-7, 2005; Stockholm, Sweden. Hot Line II. Iflg. Linda Brooks. NORVIT: The norwegian vitamin trial. Medscape sept. 2005. (Ikke publiceret i trykt medie)
3. Spence DJ et al. Vitamin intervention for stroke prevention trial. An efficacy analysis. Stroke 2005;36:2404-2409.

You Must Plug The Hole Before The Boat Sinks

October 11, 2005

A Norwegian study has shown that if you have already experienced an acute myocardial infarction, the risk of another such infarction will not be reduced by taking folic acid, Vitamin B6, and Vitamin B12, even if homocysteine levels are lowered thereby.
If you get a great deal of folic acid, the blood content of the amino acid homocysteine will be relatively low. So much is certain. When the content is low, the risk of blood clots in the heart or brain hemorrrhage – other things being equal – is also low. It is also safe, but both are statistics only.

With these facts in the bag, one is tempted to think that supplementation with folic acid must be a good idea. As you know, folic acid is the B vitamin that young women should take to avoid having children with spina bifida. One can agree with the American Heart Association, which advises everyone to get 0.4 mg of folic acid a day, the same dose that women should take as a supplement.

In Tromsø in Norway, the so-called NORVIT trial (Norwegian Vitamin Trial) was the first to test whether supplements also help heart patients who have already had a blood clot in the heart. If the media is to be believed, it ended with a scare.

The results, which were presented in September at this year’s congress of the European Society of Cardiology (ESC), led directly to warnings against folic acid in the press: B vitamins could be dangerous for heart patients, it said, and our own Danish heart association was quick to announce, that folic acid is “still” not recommended for heart patients – even though the month before was said something close to the opposite.

But, as is so often the case, the reports were misleading. Strictly speaking, the Norwegian trial did not show that folic acid is dangerous. If you want to argue that it showed anything at all, it was that the risk of heart attack, stroke, or death decreased—albeit by only a few percent—in those who took 0.8 milligrams of folic acid a day for 3.5 years . However, this was not statistically certain.

The fact is that there were in fact not one, but three trials, with a total of 3,750 people, all of whom had had blood clots in the heart. One showed that a combination of folic acid, vitamin B6 and B12 led to approx. 20% more cases of blood clots in the heart than placebo (cheat pills). The second – the only one where only folic acid was used – showed no difference in reality. There was also no difference in the third trial, where the participants only received vitamin B6.

In one area, the experiments turned out to be successful: those who received folic acid achieved a drop in the blood homocysteine content of approx. 30%. Enough so that one could hope for a nice drop in the number of new blood clots. Which did not appear.

But the questions arise: Is it appropriate for heart patients to be careful about taking folic acid, vitamin B6 and vitamin B12 at the same time?
Or are we talking about completely different anatomical conditions with secondary prophylaxis than there are with primary prophylaxis? After all, you have had a blood clot.

Also at the congress, the ESC’s designated commentator, Ian Graham, doubted the result. He believed that the experiment might have been too small and too complicated to be credible.

One can go a step further and think that the result is purely due to chance. In any case, it is not supported by any theory.
It is more likely that folic acid is simply not suitable for preventing blood clots in severely arteriosclerotic patients. – In other words secondary prophylaxis.

There is a lot of evidence that folic acid – and low homocysteine – slows the development of atherosclerosis in healthy people – i.e. primary prophylaxis. But the usefulness of this function diminishes when the calcification is already very advanced. The bottom plug must be inserted before the boat is sunk.

If folic acid is to prevent blood clots, you probably have to start in good time. On the other hand, the vitamin has other benefits. Among other things. experiments convincingly indicate that it helps to keep the brain young, even in the elderly.

By: Vitality Council

Bonaa KH. NORVIT: Randomized trial of homocysteine-lowering with B-vitamins for secondary prevention of cardiovascular disease after acute myocardial infarction. Program and Abstracts from the European Society of Cardiology Congress 2005; September 3-7, 2005; Stockholm, Sweden. Hot Line II. Iflg. Linda Brooks. NORVIT: The Norwegian vitamin trial. Medscape Sept. 2005. (Not published in a printed media).