Thiamine for anxiety?

June 4, 2008 3:29 PM

Is Vitamin B1 (Thiamine) effective for generalized anxiety disorder?

My friend is taking B1, 200mg, 3x a day, as a advised by his doc as a palliative for anxiety. Anyone have any experience with its effectiveness?

posted by Drohan to health & fitness (9 comments total)

I have tried niacinamide which is a form of B3 and a general B-complex with minor effectiveness. Your friend might also try magnesium supplements as they are more strongly associated with anti-anxiety effect.
posted by norabarnacl3 at 3:39 PM on June 4, 2008

Tell ya what, I don't know which B is is, because I take a huge Multi B, but HELL YES.
posted by Ambrosia Voyeur at 3:47 PM on June 4, 2008 [1 favorite]

Taking B vitamins has only ever given me fluorescent yellow pee. Zinc, however, helps me immensely with anxiety and insomnia.
posted by stavrogin at 3:48 PM on June 4, 2008

My uncle has an unusual kind of anemia which causes B deficiencies and without supplements he suffers from crippling anxiety.
posted by fshgrl at 4:14 PM on June 4, 2008

No clue, but I know I sleep better when I take my multivitamins at night. And that stuff is in it. So, maybe?
posted by gjc at 4:40 PM on June 4, 2008

I was confused and read "thiamine" as niacin. Please ignore my previous post - I've flagged it as noise.

There is also no real evidence that thiamine alleviates anxiety. In cases of extreme nutritional deprivation (that come with starvation or chronic alcoholism), thiamine supplements can reverse or arrest some of the neurological degeneration. But this is an acute effect where the disease process reaches maximum within only a few weeks of thiamine deprivation.
posted by meehawl at 5:05 PM on June 4, 2008

If the anxiety involves a certain level of self-medication with alcohol, doctors do have a concern about deficiency in B1. I've also been told it can counteract some side effects of certain medications. If none of this applies, carry on.
posted by hungrysquirrels at 5:43 PM on June 4, 2008

A search on pubmed for thiamin and anxiety doesn't reveal any research into this. I've actually been looking at this kind of stuff recently, though more with depression, bipolar disorder and schizophrenia than anxiety per se. The only B vitamin supplement with any real evidence behind seems to be folate (AKA Vitamin B₆). There are other reasons for taking B vitamins, including poor nutrition and impaired absorption, but most healthy people aren't deficient in B vitamins (or, generally speaking, any other vitamins).

Because mental illnesses like anxiety have a large response to placebo, anecdotal evidence should be treated with caution. This doesn't mean people haven't got better from taking vitamin supplements, it just means that (for example) a lump of clay labelled as a vitamin supplement may have worked just as well. Or not.

It's also worth noting that 600mg of thiamin per day is a really big dose. The RDA for thiamin is around 1.4mg. The Food Standard Agency, who regulate this kind of thing in the UK have a risk assessment for thiamin, which notes that although thiamin is generally regarded as fairly non-toxic there are a very small number reports of adverse effects at these kinds of doses.
posted by xchmp at 6:59 PM on June 4, 2008

There's lots of published research about B vitamin deficiencies but I have not heard of a proven benefit to megadosing B vitamins in absence of a deficiency. Here is Wikipedia's list of the symptoms associated with deficiencies of each B vitamin. Vitamin B12 and B9 (folic acid) deficiencies are fairly common, so supplementation with B vitamins has gained a reputation as a "miracle vitamin cure". It's generally pretty safe to take B vitamin supplements because excess is shed, though of course there is such a thing as too much.

Your friend's doc could think your friend has a nutritional deficiency/absorption issue, or think your friend drinks too much alcohol. Or they could have access to research that isn't on PubMed yet. Or they could be easily swayed by woo. Without more info it's tough to say which is true and why the doc is focusing on thiamin instead of the whole spectrum of B vitamins.
posted by rhiannon at 9:31 PM on June 4, 2008