The Science and Signs of Vitamin B6 Deficiency

A group of substances necessary for cell growth, function and development, vitamins are vital micronutrients. There are 13 essential vitamins known to us; since most of them cannot be produced by the body, obtaining vitamins regularly from outside sources is a necessity.  

While vitamin deficiencies are common, they are rarely clinically detected until the condition turns severe. One study by the National Institute of Nutrition in Hyderabad reported that many urban Indians who appear healthy are vitamin deficient. Among all vitamin deficiencies, vitamin B6 was the second most commonly deficient vitamin, seen in 46 % of the population studied. 

What is Vitamin B6 (Pyridoxine)?

Vitamin B6 is a water-soluble vitamin comprising the vitamers - pyridoxine, pyridoxal, pyridoxamine, and their phosphorylated derivatives. It is one of the primary components in the cells of any living organism.

Vitamin B6 is present in foods such as meat, fish, nuts, beans, grains, fruits, and vegetables. At times, this type of vitamin is also added to foods as a supplement to snacks, power bars, and powders. In addition, there are many multivitamin preparations for adults and kids where vitamin B6 is a primary nutrient.

What Makes Vitamin B6 Special?

• Involved in the metabolism of all three macronutrients—proteins, lipids, and carbohydrates.
• Participates in over 100 enzymatic processes in the body.
• Promotes cognitive growth: Helps in the production of neurotransmitters (the body's chemical messengers) - serotonin and dopamine.
• Crucial for the immune system function.
• Necessary for the production of haemoglobin. 
• Plays a significant part in preventing vitamin B3 shortage.

So it is needless to say that a lack of this vitamin leads to various health problems.

How Much Vitamin B6 Do You Need?

The amount of Vitamin D6 you need primarily depends on your age. For example, infants 7 to 12 months old require 0.3 milligrams daily. This requirement will vary starkly for an adult. Here is a look into the vitamin B6 requirements of individuals based on their age.

• Men 2.0 mg/day
• Women - 2.0  mg/day
• 1- 9 years - 0.9-1.6 mg/day 
• 10-17 years - 1.6–2.0 mg/day
• 0–6 months  - 0.1 mg/day 

Since B6 goes to the infant through breast milk, lactating mothers must have 2.5 mg of B6 daily.

What Happens When You are Not Getting Enough of Vitamin B6?

People with low vitamin B6 levels may not exhibit any signs or symptoms for months or even years. Symptoms of early or subclinical vitamin B6 insufficiency can be hazy or transient. Here are some changes to watch out for:

• Skin changes: Seborrheic dermatitis, pellagra-like dermatitis and nonspecific scaly itchy rash.
• Decreased immunity: Recurrence of infections.
• Peripheral Neuropathies: Tingling or burning sensation in hands and feet.  
• Cheilosis/Cheilitis: Appears on lips as fissuring, crusting, scaling and lesions at the corner of lips.
• Glossitis: Inflamed, red and swollen tongue.
• Stomatitis: Inflammation inside the mouth noted as red areas and/or ulcers  
• Behavioural changes: hyperirritability, altered alertness, mood swings, depression and disorientation.
• Ataxia: Impaired coordination and balance, with abnormal head movements.
• Hyperacusis:  sound or noise sensitivity.
• Convulsions and seizures in adults and infants.
• Microcytic anaemia: manifests as weakness and tiredness.
• Sleeplessness.
• Electroencephalographic (EEG) changes: manifests as abnormal brain activity.
• Impaired glucose tolerance.
• Impaired platelet function.

Who is at Risk of Developing Vitamin B6 Deficiency?

Besides low nutrient intake, there are other factors that lower the level of B6; if you have any of the following, the chances of developing Vitamin B6 are high.

• Increased protein consumption.
• Use of medicines like Isoniazid (used to treat tuberculosis) and Theophylline (used in asthma).
• High-dose of oral contraceptives.

• Excessive alcohol consumption.
• The level of B6 decreases further reduces during pregnancy-related complications like preeclampsia or eclampsia
• Impaired kidney function
• Auto-immune disorders like Rheumatoid arthritis and Mal-absorptive disorders, including Inflammatory bowel disease, Celiac disease.

How to Prevent Vitamin B6 Deficiency?

Vitamin B6 is found in many foods of both plant and animal origin; however, the bioavailability of plant sources is less, so vegans and vegetarians are more likely to become B6 deficient.

Among the plant-based sources of Vitamin B6, the following are effective:

• Wheat bran 
• Whole grain cereals and legumes
• Fruits:  bananas, apples, oranges, 
• Nuts:  Walnuts 
• Vegetables - potatoes

Among sources of Vitamin B6 found in animals, liver, lean meat, milk, pork, yeast, chicken, salmon, and fish are a few options worth mentioning.

Synthetic sources of vitamin B6 include fortified foods like rice, pasta and soya.

What are the Side-Effects of Excessive Consumption of Vitamin B6?

The tolerable upper intake level of vitamin B6 for adults is 100 mg/day; when used as part of a healthy diet, vitamin B6 is not toxic. Excess consumption of Vitamin B6 might cause patients to develop painful skin lesions, nausea, heartburn, photosensitivity and sensory neuropathy that renders them unable to walk.

Testing and Treatment

Blood samples are tested through HPLC to measure Vitamin B 6 in blood . Values less than 8.7 ngl/mL suggest vitamin B6 insufficiency 

Homocysteine is an amino acid broken down by vitamins B12, B6, and folic acid. High homocysteine levels in the blood can indicate a vitamin shortage, cardiac disease, or a rare inherited illness. So, estimation of homocysteine is also diagnostic of B6 deficiency.