Vitamin B6
Vitamin B6 is a water-soluble B-vitamin involved in energy production, brain function, hormone regulation and the production of neurotransmitters such as serotonin and dopamine. It also plays a role in immune function and red blood cell formation.
Although B6 is essential for good health, it is one of the supplements most likely to cause problems when taken in high doses or for long periods. Excess vitamin B6 can irritate the nerves, leading to tingling, numbness or burning sensations, even at doses found in some stress, PMS or energy supplements.
What is vitamin B6?
Vitamin B6 (pyridoxine) is a water-soluble vitamin involved in amino acid metabolism, neurotransmitter synthesis and immune function. It has drawn research interest particularly in relation to premenstrual symptoms and mood, with modest but encouraging findings in some areas. The body does not store excess B6, so regular dietary intake is necessary.
It appears in supplements as:
Pyridoxine hydrochloride (common form)
P-5-P (pyridoxal-5-phosphate) — a more active form
Both forms can cause problems if too much is taken.
What B6 is taken for
Vitamin B6 is taken most often by people experiencing premenstrual symptoms (mood changes, fatigue, irritability), and increasingly by those interested in mood support more broadly. It is also part of general B-complex supplementation.
However, many of these areas are influenced by multiple nutrients and lifestyle factors - not B6 alone. Because high-dose B6 can cause nerve irritation, supplementation should only be used when there is a clear reason.
What does the research show?
Randomised controlled trials have examined vitamin B6 specifically for premenstrual syndrome (PMS), with some showing significant benefits for emotional symptoms (depression, irritability, tiredness) but little effect on physical symptoms (headache, bloating, breast discomfort).
Further research suggested potential efficacy in alleviating depressive symptoms more broadly, though the evidence, while encouraging, is not as robust as for some other interventions.
However, evidence also shows:
too much B6 can cause nerve problems, including tingling, numbness or burning sensations in hands or feet
B6 toxicity can happen at doses found in some high-street supplements
long-term use of high-dose B6 is the biggest risk factor for nerve symptoms
B6 deficiency is relatively uncommon in the UK
symptoms often attributed to 'low B6' can have many other causes
This makes safe use extremely important.
Where might it be considered?
Vitamin B6 supplementation may be explored in people experiencing premenstrual mood symptoms, particularly those with confirmed deficiency. B6 may also be helpful when:
a recent blood test shows low B6
there is low dietary intake of B6-rich foods
hormone or neurotransmitter pathways have been reviewed as part of wider testing
pregnancy-related nausea is being managed under GP/midwife guidance
B6 should not be used simply because of tiredness, low mood or stress. These symptoms have many possible causes.
When to be cautious
Vitamin B6 requires careful use because too much can affect the nerves. Very high doses of vitamin B6 (typically >500 mg daily) can cause nerve damage (peripheral neuropathy) with chronic use. Additionally, people on certain medications (including some antidepressants and Parkinson's medications) may have interactions. Those with existing nerve concerns or on medications should discuss B6 supplementation with a healthcare provider.
You should also take care if you:
take a multivitamin or energy supplement that already contains B6, particularly PMS, stress, energy or hormone balance blends, which often contain high doses.
notice tingling, numbness or burning sensations - signs that B6 may be too high
have a history of nerve issues
are pregnant (only specific doses are safe)
take medications processed by the liver (B6 can change how your body handles some medicines)
Why it is not a complete mood solution
Premenstrual mood changes and depression are influenced by hormonal fluctuations, stress, sleep, overall nutrition, exercise and underlying mental health patterns. Using B6 alone without addressing these factors is unlikely to produce the improvements sometimes hoped for.
Before considering B6 supplements, look at your:
overall protein intake (B6 works closely with protein metabolism)
meal timing and blood sugar balance
sleep quality
stress load and recovery
other B-vitamins (especially B12 and folate)
whether existing supplements already provide B6
Food-first B6 support
Vitamin B6 is naturally present in chickpeas, salmon, chicken, potatoes, bananas and many other foods. For most people eating a reasonably varied diet, B6 deficiency is uncommon in developed countries. Rather than supplementing, ensuring adequate intake through food (particularly legumes, whole grains, animal protein and vegetables) supports both B6 status and the broader nutrient context that influences mood and menstrual health.
Food sources rarely cause problems because the body regulates B6 from food more effectively than from supplements.
B vitamin confusion?
If you’re considering B vitamins for mood, energy, hormones or stress, we can look at your diet, symptoms and any recent blood tests to see whether it’s appropriate. Book your free call with me.
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