Vitamin B6 & Health
Necessary for over 100 different body processes, vitamin B6 is especially important in protein metabolism. (1) This week, we will look at this vitamin to investigate its role in our health, diseases, and how we can find this key nutrient in our food.
What is Vitamin B6 & What Does it Do?
Vitamin B6 is another of our water soluble B vitamins. It gets its name from the six chemical forms it is found in naturally. One specific form, pyridoxal 5’ phosphate (PLP) is used in over 4% of the thousands of enzymatic reactions that occur in our bodies! (1) Like many of the other nutrients we have explored this year, human bodies cannot make our own B6, so we must consume it.
A few important things B6 involves itself in are: (1)
The creation of hemoglobin - the protein in our blood that carries oxygen and carbon dioxide
The creation of amino acids
The breakdown of fat into energy
The breakdown of protein into energy
The release of stored glucose from the liver - this is very important during times of fasting - even short-term fasting such as during sleep
The creation of some nucleic acids - part of our DNA
The effects of steroid hormones such as estrogen and testosterone on the cellular level
Disease Prevention:
Let’s first look at vitamin B6 deficiency to better understand what happens when we do not get enough B6. Unlike some of the other vitamins we have studied, B6 deficiency doesn’t have a specific name; this is due to the rarity of B6 deficiency. We see it more in those who suffer from alcoholism due to the effects of alcohol on diet and metabolism. In the 1950s, we unfortunately saw B6 deficiency in another population: infants. This was due to infant formula that was manufactured without the vitamin added. (1)
Symptoms of Vitamin B6 Deficiency: (1)
Seizures
Irritability
Depression
Confusion
Inflammation of the tongue
Sores in the mouth
Ulcers at the corners of the mouth
In addition to avoiding the symptoms of B6 deficiency, we also see a potential role for B6 in the prevention of immune dysfunction, cardiovascular disease, cognitive decline, depression, cancer, and kidney stones.
With each of these areas, vitamin B6 doesn’t appear to be working alone; folate and vitamin B12 play especially important roles in the inflammation seen in immune dysfunction, cardiovascular disease, cancer, and cognitive decline. (1)
Treatment of Disease:
When it comes to the treatment of disease, B6 is an important component in the treatment of many metabolic diseases associated with epilepsy. B6 also shows some promise as a treatment for the morning sickness associated with pregnancy, carpal tunnel syndrome, depression, and premenstrual syndrome. (1)
Remember, when using a nutrient to treat a condition, always consult with your medical team for monitoring, dose adjustments, and assessments for efficacy. When we switch from supporting our good health to a focus on treating disease, the dosage and cost tend to increase and toxicity becomes a concern.
Toxicity:
Vitamin B6 does have some very real toxic effects when taken to excess. Sensory neuropathy, which begins with pain and numbness in the extremities, can lead to difficulty with walking and the activities of daily living. This has only been seen with supplementation and has been documented with doses between 500 and 200 mg or higher. The Upper Limit (UL) for vitamin B6 has been set at no more than 100 mg daily to prevent this painful and debilitating condition. (1)
Where to Find Vitamin B6:
B6 is found in many different foods. However, the B6 found in plant foods tends to be less bioavailable than that found in animal products. For this reason, those on a strictly plant-based diet should be strategic in their food consumption to get enough of this needed nutrient.
Foods particularly rich in B6 include: (1)
Salmon
Potatoes
Turkey
Avocado
Chicken
Spinach
Bananas
Fortified cereals
As to supplements, B6 is a part of all multivitamin and B complex formulas. It can also be found as a standalone supplement, but I do not recommend taking it in this form, both to avoid toxicity and to ensure that you are not supplementing B6 at the expense of folate, B12, or niacin.
Applications:
Our takeaways this week are:
Since we cannot make B6 and we need it to function, let’s ensure we get it in through our diets.
The form of B6 commonly available in plants tends to be poorly absorbed, so care should be taken for those on a plant-based diet.
Supplementation of B6 on its own isn’t the best idea for several reasons, and it should only be done under the supervision of a doctor to avoid painful sensory neuropathy.
Daily Intake:
The minimum daily intake (RDA) to avoid deficiency is 1.5-1.7 mg for adults and the upper limit to avoid toxicity is 100 mg. (1) This leaves quite a bit of room for interpretation.
The Linus Pauling institute recommends taking a multivitamin daily with less than 2 mg of B6 and eating a diverse diet that includes food sources of B6. (1) I concur with this recommendation for general health.
If you think you need more than this amount, be sure to speak with your health team to determine the right target for you.
Medication Interactions:
There are certain medications that interfere with the metabolism of B6, so those taking these medications may need more B6 in their diets. These medications include: (1)
Oral contraceptives
Anti-tuberculosis medications
The metal chelator penicillamine
L-Dopa
Theophylline
Long-term NSAID use
High doses of B6 have also been found to interfere with the effectiveness of L-Dopa, phenobarbital, and phenytoin, so care should be taken with those utilizing these medications. (1)
Next week, we will look at our next B vitamin: B7 - Biotin.
To our health!