Vitamin B6 Deficiency Symptoms You May Not Know [AU] 2023
Vitamin B6, otherwise known as pyridoxine, is an essential water-soluble B vitamin. Like other B-complex vitamins, your body cannot store large amounts of B6, so you must consume enough of this vitamin daily to stay healthy and strong.
Many different foods provide some B6, so a serious deficiency is rare. However, marginal vitamin B6 deficiency is common and associated with an increased risk of inflammatory diseases, including heart disease and some types of cancer. Moreover, B6 is essential for normal brain development, so achieving adequate intakes during pregnancy is critical.
B6 also plays a critical role in the immune system, autoimmune disorders, and some chronic diseases. For example, dietary B6 has been shown to modulate the progress of inflammatory bowel disease, with a dietary deficiency worsening this condition.
In this article, we cover the symptoms of a vitamin B6 deficiency to be aware of, the risks of not getting enough in your diet, and whether B6 is one of the vitamins you should supplement.
Vitamin B6 Deficiency Symptoms
Vitamin B6 is involved in over 150 chemical reactions in the body, and a deficiency can increase the risk of multiple chronic diseases. The risk of B6 deficiency rises as you age and in those with some autoimmune disorders, certain medications, and alcohol dependence.
The main symptoms of B6 deficiency are:
- Mental health issues.
- Fatigue and poor sleep.
- Reduced immune function.
- Skin rash.
- Tingling in extremities.
- Sore lips and tongue.
- Decline in cognitive performance.
- A marginal vitamin B6 deficiency is common in the general population due to a low variety of intake of fruits and vegetables.
- In the United States, 10.5% of the population is deficient in B6. Those with sufficient levels of this nutrient had a 15% reduced risk of all-cause mortality and a 19% reduced risk for heart disease. Thus, a long-term deficiency can even increase your risk of heart disease and cancer.
- Symptoms of B6 deficiency include anxiety, depression, and cognitive decline.
What Is Vitamin B6 Deficiency?
A B6 deficiency is when you have a suboptimal dietary intake of pyridoxine or when you have low serum levels of this vitamin and its various active forms.
In the United States, 11% of supplement users and 24% of those who do not take supplements have inadequate levels of B6, and one recent study claimed that almost 13% of the population is outright deficient in B6.
One deficiency parameter can be defined by blood tests where less than 20 nanomoles/liter is considered B6 deficient. However, B6 status isn’t easy to diagnose because of several potential confounders. Hence, medical professionals usually assess deficiency using a combination of biomarkers, such as inflammation, alkaline phosphatase activity, serum albumin levels, renal function, and inorganic phosphate levels.
Signs Of Vitamin B6 Deficiency
Here are the most common low vitamin B6 symptoms.
Mental Health Problems
B6 is required by the body to help magnesium work to balance stress levels. These nutrients are both co-factors needed to convert tryptophan, an essential amino acid, into physiologically important metabolites, including serotonin and melatonin.
Studies show that those who are magnesium-deficient experience greater improvements in stress levels and mental well-being when supplementing combined magnesium and B6, compared to magnesium alone. However, other studies suggest that adding a B6 supplement might only help in cases of severe stress.
Also, new research shows that high-dose B6 supplementation reduces anxiety and might also lower symptoms of depression. In this study, the researchers found that it worked by increasing γ-aminobutyric acid, or GABA, levels, which is a neurotransmitter that promotes relaxation requiring B6 for synthesis.
Fatigue And Poor Sleep Quality
Pyridoxine is required for the metabolism of macronutrients in the body, including carbohydrates, lipids, and proteins.
It’s specifically needed for one-carbon metabolism — a process also known as methylation — which builds neurotransmitters and red blood cells, produces energy and replicates DNA. Hence, it’s not surprising that a B6 deficiency might explain symptoms of fatigue and some cases of anemia, which is a low red blood cell count.
However, the tiredness and fatigue seen in those with B6 deficiency might partly be due to its effect on sleep quality.
Studies suggest that those with lower circulating pyridoxine levels are at greater risk of abnormal sleep duration — either very short or very long — and increased daytime sleepiness. Further studies suggest that supplementing with 240 milligrams of B6 before bedtime significantly increases dream recall, suggesting that B6 might be necessary for sleep regulation. Note that this is significantly above the recommended daily intake amount of an average of 1.7 milligrams daily and could only be achieved with supplementation.
Reduced Immune Function
Catching certain illnesses more frequently, especially pneumonia, COVID-19, and other viruses, might be another sign of a B6 deficiency. Since it is needed to form healthy red blood cells, it is an integral part of the hematopoietic system and, thus, the immune system.
B6 metabolism has been shown to regulate T-cell anti-tumor function, suggesting once again that the vitamin plays an important role in cancer prevention and immune system function. Multiple studies suggest that increasing B6 intake via diet or supplementation improves some immune functions in those who are B6 deficient.
Pyridoxine, a form of B6, is crucial for skin health and epidermal function. A B6 deficiency can cause skin problems such as a type of red, itchy, flaky facial skin rash called seborrheic dermatitis.
Transdermal delivery of vitamin B6 directly into the skin is considered a safe treatment for facial seborrheic dermatitis. Also, B6 was discovered to be a good treatment for dermatitis in rats.
Other symptoms that might suggest a B6 deficiency, but are also signs of deficiencies in other B vitamins, such as in folic acid or vitamin B12, include:
- Cracked lips, especially in the corners.
- A smooth, glossy tongue.
Risks Of Vitamin B6 Deficiency
Apart from the symptoms explained above, there are multiple risks of a B6 deficiency that might not be immediately obvious.
Type 2 Diabetes
B6 is essential for carbohydrate metabolism and balances blood sugar levels. That’s partly why low B6 status is associated with developing type 2 diabetes.
B6 also helps reduce the formation of advanced glycation end-products, which are harmful compounds that develop with aging and cooking at high temperatures and are usually high in those with diabetes.
Studies suggest that B6 status is linked with cancer risk.
Specifically, lower B6 levels are associated with significantly higher colorectal cancer risk, especially in males and smokers. Also, a higher turnover of vitamin B6, which might be due to its use as an antioxidant and in fighting cancer, is seen in those at an increased risk of all-cause mortality and cancer mortality.
As already mentioned, B6, alongside folic acid and vitamin B12, is crucial for regulating a process called one-carbon metabolism or methylation. This process regulates DNA synthesis and the building of new cells. When this process becomes dysregulated, it can increase the risk of cancer.
Scientists also think vitamin B6 has anti-inflammatory and antioxidant properties, meaning that higher B6 levels might further protect against cancer.
However, other studies suggest that B6 status might indicate the status of other dietary protective micronutrients, meaning that vitamin B6 status itself might not be directly related to cancer risk.
A vitamin B6 deficiency might increase age-related artery stiffness, which is associated with high blood pressure, reduced blood flow to the brain, and cognitive impairment.
Studies in mice suggest that treatment with vitamin B6 as pyridoxamine treatment reduces artery stiffening, protects mice from age-related blood pressure rises, and partially improves cognitive function.
A deficiency in vitamin B6 is associated with high homocysteine levels, which is linked to cardiovascular diseases such as heart disease and stroke.
Vitamin B6-deficient diets are also linked to lower levels of omega-3 fatty acids important for health, including docosahexaenoic acid, eicosapentaenoic acid, and arachidonic acid.
Poor Pregnancy Outcomes
Studies suggest that pregnant and lactating women are at an increased risk of insufficient vitamin B6 levels. Further studies suggest that supplementing pregnant women with vitamin B6 improves DHA levels, which is crucial for fetal development.
What’s more, B6 can reduce morning sickness in pregnant women, with B6 supplementation reducing nausea and vomiting in the first trimester.
Risks Of Too Much Vitamin B6
Peripheral neuropathy may develop in individuals consuming excessive doses of B6 for prolonged periods. Peripheral neuropathy is characterized by numbness and tingling in the extremities caused by products containing less than 50 milligrams of B6 per serving.
Products now containing more than 10 milligrams of B6 should warn about the possibility of developing peripheral neuropathy, and the government advises that sources of B6 from all dietary supplements be considered in totality. Products cannot provide more than 100 milligrams daily of this nutrient, and lower amounts are allowed for children, effective as of March 1, 2023.
Foods High In Vitamin B6
A lack of dietary variety is usually the main cause of B6 deficiency. As the human body cannot store a lot of vitamin B6, you need to ensure you consume enough regularly.
Most individuals between the ages of 4-50 need a recommended daily intake or RDI of 1.7 milligrams of B6 per day, a value which increases to 1.9 milligrams in pregnancy and 2 milligrams in breastfeeding. RDIs represent the bare minimum that the body needs to survive and prevent deficiency.
Plant foods are the major sources of vitamin B6 in the diet, with cereals and potatoes being the highest, and studies show that vegetarians have significantly higher vitamin B6 status.10] Even in omnivores, studies suggest that foods from plant sources provide more than 70% of dietary vitamin B6 intake.
However, getting sufficient vitamin B6 from the diet can be hard, and scientists have been working on genetically engineered plants with higher vitamin B6 levels.
The main food sources of vitamin B6 are:
- Poultry, such as turkey or chicken breast.
- Other meat, such as pork or beef liver and other organ meats.
- Fish, such as halibut and wild-caught salmon.
- Vegetables, especially potatoes, red bell peppers, and Brussels sprouts.
- Fruits, especially bananas, prunes, and avocados.
- Nuts and seeds, especially roasted pistachio nuts and sunflower seeds.
- Fortified foods.
It’s best to get vitamin B6 from your diet rather than supplements. In rare cases, there can be serious side effects from supplementing very high doses of B vitamins, such as:
- Acute liver toxicity.
- Nerve damage due to vitamin B6 toxicity, leading to peripheral neuropathy.
If supplementing, the bioactive form of pyridoxal 5’-phosphate is recommended over pyridoxine supplements because of a lower risk of neuronal toxicity. This is the type of B6 needed by the human body.
However, other sources suggest that pyridoxine hydrochloride is the preferred supplemental form because it’s the most stable and easily converted into its active form in the body.
Vitamin B6 is an essential water-soluble vitamin involved in more than 150 chemical reactions in the body. It’s crucial for regulating mood, energy levels, and immune function and might even have anticancer properties.
While overt vitamin B6 deficiency is uncommon, a marginal deficiency is common in the general population. This is usually due to a lack of dietary variety of plant-based foods. The best way to ensure you’re getting enough vitamin B6 is to eat various plant-based foods daily.
The symptoms of a vitamin B6 deficiency are similar to that of other nutrient deficiencies, so it’s difficult to diagnose without diagnostic tests. If your symptoms don’t subside after a few weeks or worsen, go to your doctor and get a blood test to check your nutrient levels.
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