You can find lots of websites recommending B vitamins for depression, some offering high strength vitamin B supplements for lifting “mood naturally” – like this website, which sells vitamin B6 along with a claim that it can help to relieve premenstrual symptoms and depression.
Oddly, the website selling vitamin B6 – whose nutritionists “recommend 50mg of B6 a day for optimal health” – doesn’t mention that the “safe upper level” for long-term consumption of this vitamin is 10mg per day (for a 60kg adult) or the reasoning by which this safe upper level was determined. My source for the safe upper level is this huuuuge PDF: http://cot.food.gov.uk/pdfs/vitmin2003.pdf.
The page for vitamin B6 on this website does have a set of tabs you can click on for further information, and one of these tabs is headed “caution”. This is the only one of the five tabs that contains zero information. Apparently, linking to articles on their website penned by such luminaries as Ann Walker is more important than mentioning the safe upper level for this vitamin – or the fact that the review of the safety of vitamins and minerals I link to above stated that “excessive quantities of vitamin B6 result in peripheral neuropathy in both animals and humans“.
It’s not just websites that carry claims that vitamin B supplements can help with depression. There’s also the media nutritionists such as Patrick Holford, who has written a book titled “Optimum Nutrition for the Mind“.
In this book, Patrick claims that “the most promising nutrients for improving mood are vitamins B3, B12 and folic acid, then vitamin B6…” but no reference is provided to support this claim.
Holford does mention a study that looked at folic acid, but in this case it was given in huge doses alongside standard drug treatments. The researchers studied a small number of subjects with major depression or schizophrenia. It seems (as far as I can tell from the abstract) that the researchers recruited from 123 subjects and that only those 41 patients who had “borderline or definite folate deficiency” were included in the trial. [Link to abstract.]
If your best evidence for a claim that a number of vitamins are “promising” with regards improving mood is a single small study that looks only at a very specific group of people, in which only one of the named vitamins was given to participants (and given alongside conventional treatment), then forgive me if I regard your claim with scepticism.
Later in the book, in a chapter headed “Overcoming Depression”, Patrick recommends 100mg of vitamin B6. There is no reference to the safe upper level for this vitamin (just 10mg per day for adults) and no mention of the possibility of peripheral neuropathy or any other adverse effect.
He also claims that it helps “tune up the brain” and increase levels of SAMe. The reference for this claim is a paper from 1993 by R Crellin et al, which is behind a paywall. I’m not going to purchase an old paper cited by Patrick Holford just to check whether it supports his claim. I will be charitable and assume that Patrick’s interpretation of the paper is flawless.
There are more recent papers, though, which describe trials conducted using vitamin B6 for depression. Let’s take a look.
One study looked at the “relationship between dietary vitamin B6 and concentrations of pyridoxyl-5′-phosphate (PLP) with depressive symptomatology” in 618 elderly Caribbean Hispanics, and a group of 251 non-Hispanic white older adults in Massachusetts:
RESULTS: PLP was significantly associated with CES-D score and depressive caseness in the total sample and in non-supplement users. Deficient levels of plasma PLP (plasma PLP < 20 nmol/L) approximately doubled the likelihood of depressive caseness. Total intake (diet + supplement) of vitamin B(6) was not associated with these outcomes. However, dietary vitamin B(6) was significantly associated with CES-D score and depressive caseness. CONCLUSION: Longitudinal studies are needed to clarify the direction of causality between vitamin B6 and depressive symptoms.
Depressive symptoms in these older people were associated with dietary vitamin B6 but not with total intake. This does not seem to support Mr Holford’s recommendation to pop 100mg pills of vitamin B6. This paper looked at severity of depressive symptoms and incidence of clinically significant depression.
The investigators recruited 299 men aged 75 years and older free of clinically significant depression (Beck Depression Inventory [BDI] score < 18). They were randomly assigned to treatment with 400 microg B(12) + 2 mg folic acid + 25 mg B(6) per day (N = 150) or placebo (N = 149). The BDI was the primary outcome measure of the study. […] Analysis of variance for repeated measures showed that there was no difference between the groups (F = 0.76, df = 1, p = .384) nor was there a significant change of BDI scores over time (F = 1.26, df = 4, p = .284). […] CONCLUSION: The results of this study showed that treatment with B(12), folic acid, and B(6) is no better than placebo at reducing the severity of depressive symptoms or the incidence of clinically significant depression over a period of 2 years in older men.
In this study in older people, the B vitamins failed to perform any better than placebo. This does not seem to support Mr Holford’s recommendation to pop 100mg pills of vitamin B6.
Maybe the B vitamins need to be taken together in order to work? Or perhaps you need to take pills containing all the essential vitamins? Well, there’s an interesting little paper here that compared multivitamin, B-complex vitamin, placebo vitamin, or no-treatment. Perhaps unsurprisingly, those in the “no treatment” group did less well than the other subjects. Those given the placebo ‘vitamin’ pill, however, improved to the same extent as those given actual multivitamin or vitamin B complex pills:
This placebo-controlled, single-blind trial evaluated the effect of vitamins on depression symptoms experienced by a nonclinical sample of participants. One hundred and fourteen healthy young adults were randomly assigned to multivitamin, B-complex vitamin, placebo vitamin, or no-treatment control conditions. At the end of a 6-week regimen, participants administered vitamins reported significant reductions in depression symptoms as measured by the Beck Depression Inventory compared to those who received no treatment. There was no difference between the multivitamin, the B-vitamin, and the placebo. The effect of each of the vitamin regimens on depression symptoms was partially mediated by response expectancies. The results do not support the efficacy of vitamins as a natural remedy for reducing or preventing depression symptoms among healthy people in the general population.
Holford and Healthspan claim (respectively) that 100mg or 50mg of vitamin B6 should be taken for “chronic or severe depression” or can “relieve depression”. I’ve yet to see the evidence for this, though. [Edit, 20th June: see also this Cochrane Review that Neuroskeptic links to in the comments below. This review found no evidence for short-term benefit from vitamin B6 in improving mood (depression, fatigue and tension symptoms) or cognitive functions.]
I even tried the list of UK health claims and could only find references to phenylalanine for depression. Vitamin B6 claims are contained in this 798 page PDF, but none relate to depression. Healthspan are based in the Channel Islands, so I’m not sure if the Nutrition and Health Claims Regulations currently apply to them, but it seems that they should: this page includes the information that “In the case of health food products, the Ministry of Justice has acknowledged that the Channel Islands should implement the relevant legislation, in particular the FSD, the NHCR and the Medicines Directive.”
Guernsey … recently confirmed that work has begun on investigating the implementation of the FSD and NHCR, but a clear timetable for implementation has still not been provided.
In January 2010, Mark Todd asked the Secretary of State for Health if the Food Standards Agency would raise at future meetings with the authorities in Guernsey and Jersey the implementation of the Nutrition and Health Claims Regulations.
The implementation of the Food Supplements Directive and Nutrition and Health Claims Regulation was last raised with the authorities of Guernsey and Jersey in September 2009. No further meetings are currently planned.
I expect that at some point prior to (or shortly after) the implementation of the Nutrition and Health Claims Regulations in Guernsey, we will see claims to the effect that ‘vitamin B6 can relieve depression’ disappear. Well, either that or someone will need to provide a plethora of evidence supporting the claim.
A little bit of trivia
There are also media reports of scientific research into vitamin B for depression: this BBC report covers research into use of vitamin B12 along with antidepressants in a study published in the journal BMC Psychiatry.
Although the report states that scientists suggest that “taking vitamin B supplements may be a way to boost the effectiveness of antidepressants”, the scientists in question said that more research was needed and were quoted as saying that:
It is still too early to suggest generally that patients should take vitamin B12 or any other vitamin supplements to treat depression.
Amusingly, of the three external links one is broken and another goes to HSIS, part of the PR arm of the food supplement industry. (Actually, perhaps that last line should have read “part of the PR arm of the lucrative food supplement industry“.)
From the HSIS website: “The Health Supplements Information Service (HSIS) is coordinated by PAGB (The Proprietary Association of Great Britain)”.
From the PAGB website: “The Proprietary Association of Great Britain represents the manufacturers of over-the-counter medicines and food supplements in the United Kingdom.”
(If I were a conspiracy theorist, I might now write some shrill comment claiming that HSIS cannot be trusted as they are shills for “little pharma”. But I’m not, so I won’t.)