Vitamin B6 benefits relate to energy production, protein metabolism and hormone balance for both men and women. In women, vitamin B6 promotes normal levels of oestrogen and progesterone and is used to help overcome premenstrual syndrome.
In men, vitamin B6 helps to regulate testosterone levels and is taken to improve erectile dysfunction, especially where this is associated with furring up of the arteries or diabetes.
In both men and women, vitamin B6 may enhance libido by decreasing the production of prolactin – a hormone that naturally reduces sex drive.
Vitamin B6 benefits
Vitamin B6 consists of a group of compounds that includes pyridoxine, pyridoxal and pyridoxamine that are all converted into the most active form, pyridoxine, in the liver. Pyridoxine is needed for over 100 enzymes to work properly. Vitamin B6 is essential for the metabolism of protein, carbohydrate and essential fatty acids to produce energy, and for the synthesis of genetic material, amino acids and brain neurotransmitters and has effects on mental processing, mood and hormone balance.
Vitamin B6 is even involved in the production of hydrochloric acid in the stomach, and for regulating salt and fluid balance to reduce water retention. It increases production of antibodies and the number and activity of immune cells (T4–helper lymphocytes) to boost immunity
Good supplies of vitamin B6 are especially needed by rapidly dividing cells such as those found in the gut, skin, hair follicles and marrow. It also works together with folate and vitamin B12 to stimulate the breakdown homocysteine – an amino acid that, if allowed to build up, damages blood vessel walls to hasten hardening and furring up of the arteries (atherosclerosis).
Within the EU, the European Food Safety Authority has authorised health claims that vitamin B6 contributes to:
- Normal cysteine synthesis
- Normal homocysteine metabolism
- Normal energy-yielding metabolism
- Normal protein and glycogen metabolism
- Normal functioning of the nervous system
- Normal psychological function
- Normal red blood cell formation
- Normal function of the immune system
- The reduction of tiredness and fatigue
- The regulation of hormonal activity
Food Sources of vitamin B6
Although small amounts of vitamin B6 are stored in the liver, muscle and brain, it is water-soluble and readily lost in the urine, so regular intakes are essential. Good intakes of vitamin B2, zinc and magnesium are also needed for vitamin B6 to work properly.
Vitamin B6 is widely found in cell-based foods, including;
- meat, especially chicken, pork, liver and kidneys
- oily fish and shell fish
- egg yolk
- whole-grain cereals, especially brown rice
- soy products
- nuts, especially peanuts and walnuts
- green, leafy vegetables
- yeast extract
Up to 70% of the vitamin B6 present in meat is lost during processing and cooking. Pasteurisation reduces pyridoxine in milk by 20%, canning lowers vegetable pyridoxine by 20%, and a further 40% is lost into water when frozen vegetables are thawed and cooked.
Vitamin B6 deficiency
A severe lack of vitamin B6 is unusual but in early experiments in which volunteers followed a die that was deficient in vitamin B6, early symptoms included mood changes with depression and a reduced sense of responsibility.
Symptoms that may be due to vitamin B6 deficiency:
- low sex drive
- greasy rash on the forehead and around the nose.
Symptoms that may be due to major vitamin B6 deficiency:
- splitting and cracking of the lips and tongue
- recurrent mouth ulcers
- red, inflamed tongue
- burning skin.
Vitamin B6 and Premenstrual syndrome (PMS)
Vitamin B6 is a popular treatment for the hormone and fluid imbalances associated with the second half of the menstrual cycle. Its effectiveness has been disputed as research has not shown a consistent association between vitamin B6 intakes and the presence of PMS. However, it’s possible that some women do not use vitamin B6 efficiently and therefore need higher intakes.
A systematic review of 9 trials involving 940 women with PMS found that a proportion of women taking vitamin B6 showed improvement in their symptoms compared with placebo. Although the conclusion was limited by the low quality of trials, the reviewers stated that doses of up to 100mg vitamin B6 per day are likely to be of benefit in treating premenstrual symptoms, including premenstrual depression.
Another study involving 60 women with PMS compared the effects of vitamin B6 (pyridoxine 100mg per day) against a prescribed medicine (bromocriptine) and ferrous sulfate iron supplements. After 3 months treatment, the women taking vitamin B6 showed a significantly higher response rate to bromocriptine and ferrous sulfate, as well as fewer side effects.
Vitamin B6 and low sex drive
Vitamin B6 is believed to enhance libido through beneficial effects on mood, sex hormone balance and by suppressing the production of prolactin hormone. This has not been well researched, however, and is largely based on anecdotal evidence from people who have found it works for them.
An early study involving women with low sex drive as a result of taking oral contraceptive pills found that doses of vitamin B6 ranging from 20mg to 50mg per day lifted depression and helped improve libido.
If you are female and have a low sex drive associated with low mood, PMS or with using hormonal methods of contraception, a vitamin B6 supplement is certainly worth trying.
Vitamin B6 and erectile dysfunction
As well as regulating sex hormone balance, vitamin B6 is involved in the breakdown of homocysteine – an amino acid which can damage artery linings when allowed to build up in the circulation. Hardening and furring up of the arteries (atherosclerosis) is a leading cause of erectile difficulties in older males and in those with diabetes. Taking vitamin B6 supplements can lower a raised homocysteine level together with folic acid and vitamin B12.
Experts commonly recommend that men who have erectile dysfunction related to raised levels of homocysteine should receive treatment to reduce this (with folic acid, vitamin B6 and vitamin B12) before proceeding to treatment with a drugs such as Viagra, Cialis or Levitra.
A study conducted at a erectile dysfunction clinic in Rome, Italy, involved 75 consecutive patients with erection problems. Their folate and homocysteine levels were measured, and all were prescribed Viagra (sildenafil citrate) for 2 months. Those who did not respond to Viagra were then given additional vitamin B6 and folic acid (as well as Viagra) for another 6 weeks. The researchers found that 88.9% of the men with high levels of homocysteine (due to the genes they had inherited) and low levels of folate reported a significant improvement in erections after taking the combination vitamin treatment in addition to Viagra.
If you have erection difficulties, a supplement that combines vitamin B6 plus folate may help if you have high homocysteine levels. It may also improve your response to Viagra. If problems persist, do seek medical advice.
Vitamin B6 and diabetes
Vitamin B6 deficiency may increase the risk of developing neuropathic nerve pain in people with diabetes, leading to unpleasant sensations of burning and pins and needles.
It is also suggested that vitamin B6 may protect against diabetic retinopathy. This followed observations in 18 people with diabetes, followed for up to 28 years, in which those who took vitamin B6 supplements did not develop retinopathy. The researchers described this discovery as ‘monumental’ however, since then, other studies have not found an association between vitamin B6 intakes and the development of diabetic complications.
Vitamin B6 and carpal tunnel syndrome
Lack of vitamin B6 has also been linked with pain associated with nerve compression in carpal tunnel syndrome.
However, when vitamin B6 levels were measured in 13 people with both diabetes and carpal tunnel syndrome, no significant differences were found between those with carpal tunnel syndrome, those without neuropathy, and normal subjects.
Although supplements are not effective in everyone, some people respond and this may be due to a change in pain thresholds. Very high doses should be avoided as these could, theoretically, cause similar symptoms due to toxicity.
Vitamin B6 dose
Requirements increase during pregnancy and lactation.
The average Western diet supplies 2 mg per day.
Multivitamin supplements and vitamin B complex include vitamin B6 at levels of between 2mg and 100mg.
Vitamin B6 safety
There were suggestions that taking prolonged high doses of above 10mg daily may cause reversible nerve symptoms such as pins and needles, but this is highly controversial as it was based on poor quality research involving surveys that asked leading questions.
The European Food Safety Authority has determined a tolerable upper intake level for long-term use of vitamin B6 in supplements as 25mg per day.
The risks associated with taking vitamin B6 at doses between 25mg and 200mg are unclear, but are probably low. Doses of 100mg or above are available, but are best used under the supervision of a medical nutritionist.
Very high doses of vitamin B6 can cause headache, acne, skin reactions, nausea, abdominal pain, loss of appetite and abnormal liver function in addition to potential nerve-related symptoms.
Do You Need A Multivitamin? My Quick Nutrition guide (46 pages) is currently free via this link
My Essential Guide to Vitamins, Minerals and Herbal Supplements offers a complete overview of each vitamin, mineral, dietary oils and herbal remedy.
Image credits: comeirrez/shutterstock