Dr Jess:Like many doctors I was taught to mainly think about thiamine (B1) and B12 when considering low B vitamin levels, but B6 has emerged as being just as critical. It is particularly important for the brain and mood . Vitamin B6 is a necessary co-factor for making serotonin (our happy hormone), dopamine (helps motivation and GABA (calms the nervous system) – important neurotransmitters in the brain. It is worth considering a multivitamin with good levels of all the B vitamins to maintain your levels if you think you may be low…
Vitamin B6 also called Pyridoxine, is a water-soluble vitamin (this means it is carried in the bloodstream and eliminated in the urine) and that it can be destroyed by heat – cooking and processing.
It is a critical vitamin for the brain and nervous system, helping make myelin a protective fat around our nerves. It is also very important for making blood, protein metabolism and immune function…
B6 is important for the immune system and inflammation
Vitamin B6 has been shown to be low in inflammatory conditions and B6 deficiency increases the risk of chronic diseases like cardiovascular (heart disease and stroke) and some cancers (1). When vitamin B6 is given to critically ill patients over 2 weeks there was a significant improvement in their immune system cells (2).
Vitamin B6 has also been shown to be a powerful antioxidant and may reduce homocysteine levels (3).
B6 is essential for forming neurotransmitters like serotonin, dopamine and GABA in our brain that regulate our mood…
Patients at risk of Vitamin B6 deficiency are those with a poor diet and women taking the oral contraceptive pill, who have been found to have lower levels of Vitamin B6 and B12 (6). Patients taking COX inhibitors like aspirin or ibuprofen are also more likely to have low Vitamin B6 levels (7).
Vitamin B6 can reduce the risk of cancer, Parkinson’s and cardiovascular disease…
Studies show that your chance of getting cancer is higher if your Vitamin B6 levels are low (8) and particularly gastrointestinal (stomach and bowel) cancers.
Vitamin B6 has been shown to significantly reduce the risk of Parkinson’s disease (9) particularly in those people who have smoked.
Heart disease risk is also directly related to low levels of Vitamin B6 and supplements containing several B vitamins, including B6, have been used to help cardiac autonomic dysfunction caused by pollution – heart problems triggered by pollution (10).
It may reduce diabetic complications…
Children with type 1 diabetes given B6 for 8 weeks had an improvement in inflammation in their blood vessels (11). Like Vitamin B1 (see thiamine) Vitamin B6 seems to have an important role in blood sugar, diabetes and its complications. Vitamin B6 deficiency may contribute to the development of Type 1 diabetes (12).
It can help reduce nausea and vomiting in pregnancy…
Vitamin B6 has been known to be an anti-emetic (stop vomiting) since 1942. Studies in pregnancy show Vitamin B6 can help vomiting (13) (14) and nausea (15) so should be considered in hyperemesis gravidarum (see Vitamin B1 thiamine and also consider ginger).
Supplements may reduce migraine headaches…
Vitamin B6 supplements given daily reduced the severity and duration of migraines when given to a migraine sufferers in a study (16).
Vitamin B6 supplements can also affect sleep…
High doses of Vitamin B6 have been shown to affect sleep, particularly our ability to remember our dreams (17) and several pilot studies are investigating whether B6 could help people be able to lucid dream (have control in our dreams).
and with Magnesium could help childhood autism…
A trial of magnesium and B6 supplements for 4 weeks given to children with autism, showed a significant improvement in their behaviour and brain recordings (18). The changes were only seen when B6 was taken alongside magnesium not on its own, as we are discovering more and more, many of our essential nutrients work better together.
An earlier study showed Vitamin B6 on its own improved behaviour in autistic children (19). Studies have also shown an abnormality in the pathways of B6 in children with autism which may help explain its benefit (20).
B6 may help with hair loss and condition…
A small study of women given B6 injections for hair loss (alopecia) over 4-5 months saw a reduction in hair loss and an improvement in hair condition (21).
- Sensitivity to MSG (monosodium glutamate) – B6 deficiency has been linked with side effects from Chinese restaurant food (Chinese restaurant syndrome) where MSG – a common food additive – causes side effects such as headaches and sweating. When Vitamin B6 is given for 3 months these effects resolve (22).
- Lithium side effects – A tiny study of tremors induced by lithium showed Vitamin B6 supplements completely resolved this side effect (23).
- Movement disorders – Tourette’s and tardive dyskinesia – Small studies have shown an improvement in both tardive dyskinesia (24) and Tourette’s syndrome with Vitamin B6 supplements. This improvement is also seen in patients on schizophrenic medication, causing movement side effects (25).
- Schizophrenia – B vitamins including B6, B8 and B12 have been found to improve symptoms of schizophrenia (26).
- Childhood Epilepsy – A genetic B6- dependent epilepsy can be a rare cause of epilepsy in childhood that does not always present typically and should be screened for in all children with seizures (27).
- Hypertension (High Blood pressure) – A small study showed Vitamin B6 supplements significantly reduced blood pressure in patients with hypertension when taken daily for 4 weeks (28).
What is the best way to get my Vitamin B6 level checked?
Vitamin B6 can be checked with a blood test: plasma pyridoxal 5′-phosphate – plasma PLP. However the accuracy of this test can be affected by inflammation, low albumin, raised ALP levels and pregnancy. If any of these conditions are present then the test may not be reliable, but as yet there are no commercially available definitive tests (29). The normal range of plasma PLP is 5-50 µg/L.
How much Vitamin B6 do I need?
The recommended daily amount of Vitamin B6 is 1.4 mg daily (the amount needed to prevent deficiency) however it is very safe at much higher levels and trials use anywhere from 25mg-200mg daily. Excess Vitamin B6 is excreted in the urine and trials have show no danger to the mother or baby taking supplements in pregnancy of over 100mg daily (30). It is also likely that amounts of B6 much higher than the recommended daily amount are required to prevent Vitamin B6 deficiency in pregnancy (31).
Top 5 sources of Vitamin B6, in order:
- Chicken (cooked) – 1 breast , 1.1mg
- Tuna (yellowfin, cooked) – 1 steak, 0.9mg
- Pistachios nuts (dry roasted and salted) – 1/2 cup, 0.7mg
- Grass-fed beef (cooked mince) – 150g portion, 0.6mg
- Avocado – 1 avocado, 0.5mg
Which supplement is best?
Vitamin B6 as pyridoxine hydrochloride (HCl) is quickly and easily absorbed to increase Vitamin B6, if yours are low. Vitamin B6 supplements are regarded as very safe up to levels of 100mg and any excess is easily excreted in the urine (32). Vitamins and minerals work well together, so it is often a good idea to take a high quality multivitamin with a good level of B vitamins or a B complex.