Vitamin B6 (pyridoxine) is one of the clusters of B vitamins that helps your body to store its energy from the protein and carbohydrates in your food. Vitamin B6 also helps your body to form haemoglobin – the cells that transport oxygen around your blood (https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-b/).
The recommended dietary allowance (RDA) is 1.4mg for men and 1.2mg for women. Most people can get enough vitamin B6 from their diet, although it can also be made by bacteria in your bowel (https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-b/). Because most people can hit the RDA this way, vitamin B6 deficiency is rare.
It is worth knowing, however, that when researchers studied the blood levels of vitamin B6 in America, they found that 24% of people did not have enough. This has led some to argue that the RDA should be increased (https://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/#:~:text=Vitamin%20B6%20deficiency%20is%20associated, function%20%5B1%2C2%5D.).
Who is at risk of vitamin B6 deficiency?
There are certain groups of people who are at risk of vitamin B6 deficiency:
1) People who are obese
2) Pregnant women (especially those with eclampsia and pre-eclampsia)
3) People who are alcohol-dependent
4) People with impaired renal function
- end-stage renal disease
- chronic renal insufficiency
- people on kidney dialysis
- people on peritoneal dialysis
- people who have had a kidney transplant
5) People with autoimmune disorders
- rheumatoid arthritis
- celiac disease
- Crohn’s disease
- ulcerative colitis
- inflammatory bowel disease
What are the signs and symptoms of vitamin B6 deficiency?
This is, perhaps, a seemingly unlikely vitamin B6 deficiency sign. People with pica crave (and eat) non-food items such as dirt, clay, rocks, paper, and ice (https://kidshealth.org/en/parents/pica.html#:~:text=Pica%20is%20an%20eating%20disorder,about%20the%20world%20around%20them.). Pica can be a sign of microcytic aneamia, which is a condition where the body’s tissues and organs do not get enough oxygen (https://www.medicalnewstoday.com/articles/319050#causes-of-microcytic-anemia).
Because vitamin B6 is important in making haemoglobin, which transports oxygen around the body, a deficiency in it can lead to microcytic aneamia, and pica (https://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/#:~:text=Vitamin%20B6%20deficiency%20is%20associated,function%20%5B1%2C2%5D.).
A vitamin B6 deficiency can cause a scaly, itchy rash called suborrheic dermatitis (https://www.webmd.com/vitamins-and-supplements/ss/slideshow-vitamins-vitamin-b6-deficiency). It can usually be seen on the face and might look similar to psoriasis, eczema, or an allergic reaction (https://www.webmd.com/skin-problems-and-treatments/seborrheic-dermatitis-medref#1).
Vitamin B6 is essential for skin development and maintenance (https://link.springer.com/chapter/10.3920/978-90-8686-729-5_4) because vitamin B6 helps to increase the amount of collagen to the skin (https://www.sciencedirect.com/science/article/abs/pii/000629448390025X). Collagen is a vital protein that helps skin to maintain its structural integrity, so losing collagen can result in the skin weakening, allowing skin problems like suborrheic dermatitis to appear (https://www.healthline.com/nutrition/collagen-benefits#:~:text=Collagen%20is%20the%20most%20abundant,strengthening%20your%20bones%20(%201%20).).
3) Scaly lips with cracks at the corners of the mouth
Vitamin B6 is important for oral health, and being deficient in it can lead to problems with the mouth. One of these is something called anular cheilitis (or angular chelilosis, angular stomatitis, or perlÃ¨che). It is characterised by the following symptoms:
- inflammation of the lips
- lips that are dry and red
- cracks on one or both corners of the mouth
- the cracks can be itchy and painful
- white scabs
Angular cheilitis can also be caused by being deficient in other B vitamins, as well as external factors such as wind and cold weather. It is a good idea to make sure that you are eating enough of all the important vitamins and that you take care of your lips if you want to avoid this condition.
4) Swollen tongue (can also be smooth and glossy)
A vitamin B6 deficiency causes a condition called glossitis. The tongue becomes inflamed, and its colour and texture can also change. This happens because the small bumps that you have on your tongue begin to shrink causing the tongue to appear as shiny and red. Your tongue may also burn or itch, and it can even make it difficult to speak, eat, or swallow (https://www.medicalnewstoday.com/articles/322135).
Glossitis can be caused by a deficiency in iron (https://academic.oup.com/nutritionreviews/article-abstract/4/9/263/1841508?redirectedFrom=PDF). Since vitamin B6 is important in making haemoglobin (which carries oxygen throughout the body), being deficient in vitamin B6 can lead to iron deficiency, and thus to glossitis.
5) Low mood
One of the more surprising symptoms of vitamin B6 deficiency is low mood or even depression. Levels of B6 in the blood are measured by looking at plasma pyridoxyl-5′-phosphate (PLP) concentrations. When researchers measured PLP levels in a group of 251 people, they found that low levels of PLP were associated with higher depression scores (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2572855/).
This is likely because of the important role vitamin B6 has in forming neurotransmitters in the brain. When there is less of one of these, serotonin, this can lead you to having a low mood, or even developing depression (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2572855/).
6) Getting ill a lot
Vitamin B6 is important for the immune system to function properly. It affects the creation of the cells that the immune system uses to fight diseases (https://pubmed.ncbi.nlm.nih.gov/8302491/), such as lymphocytes and antibodies (https://www.tandfonline.com/doi/pdf/10.1271/bbb.61.1331).
Because of this, vitamin B6 deficiency can influence the process of diseases and even the growth of tumours (https://pubmed.ncbi.nlm.nih.gov/8302491/). If you don’t have enough B6, this will mean that your immune system is not able to respond as well to disease. This could mean that you will get ill more often, or your illnesses will be more severe.
Giving vitamin B6 to patients with critical illnesses improves their immune responses (https://www.researchgate.net/publication/7109317_Vitamin_B6_supplementation_increases_immune_response_in_critically_ill_patients), so increasing your level of B6 by making sure your diet is full of vitamin B6-rich foods could help your to stay well.
7) Tiredness and weakness
These are more symptoms of vitamin B6 deficiency caused by microcrytic anaemia (iron deficiency). This is a result of less haemoglobin in the red blood cells, and less oxygen being transported throughout the body (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019700/). One of the characteristics of microcrytic anaemia is weakness, tiredness, and fatigue.
It is worth remembering that even though anaemia is an iron deficiency, increasing your intake of iron is not enough to avoid it. Having enough vitamin B6 is essential.
8) Tingling in the hands and/or feet
Because of its role in a number of metabolic reactions, vitamin B6 is important for the functioning of the peripheral nervous system (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4199287/). Vitamin B6 deficiency can lead to peripheral neuropathy.
Peripheal neuropathy is when the peripheral nervous system (the nerves outside of the spinal cord and brain) become damaged. The main symptoms are:
- numbness and tingling in the feet or hands
- burning, stabbing, or shooting pain in those areas
- loss of balance and coordination
- muscle weakness (especially in the feet)
Vitamin B6 is important for the functioning of the immune system, in transporting oxygen around the body, and the functioning of the peripheral nervous system. Vitamin B6 can cause pica, rashes, scaly and cracked lips, swollen tongue, low mood, weakened immune system, tiredness and weakness, and tingling in the hands and feet. Thankfully, it is easy to get enough vitamin B6 in your diet. Vitamin B6-rich foods include:
- some fish
- soya beans
- some fortified breakfast cereals (https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-b/)
Too much vitamin B6 can be dangerous (https://ods.od.nih.gov/factsheets/VitaminB6-Consumer/#:~:text=People%20almost%20never%20get%20too,they%20stop%20taking%20the%20supplements.). It is almost impossible to get too much in your diet, but you can take too much if you have vitamin B6 as a supplement. It is always worth checking with your GP that you aren’t taking too many vitamins.
Vitamin B6 deficiency can cause pica, rashes, scaly lips, swollen tongue, low mood, weakened immune system, tiredness, and tingling in the hands and feet.