Vitamin B6 is a water-soluble molecule whose chemical characteristics affect its bioavailability, absorption, and activity. Its biologically active form for the human body is the phosphorylated one: the pyridoxal-phosphate.
Function Of Vitamin B6
Vitamin B6 is essential for several biological functions that are important for our body. It takes part in various processes as a coenzyme, for example, in protein synthesis and amino acid transformation. It is fundamental for red blood cell formation, and it is useful in preventing and treating anemia.
It is involved in carbohydrate and fatty acid metabolism as well as in energy production from glycogen. Furthermore, together with folate (B9) and vitamin B12, it helps keep homocysteine levels low in our blood, an amino acid whose high levels are connected to cardiovascular risk.
Vitamin B6, together with zinc, is useful for supporting the good functionality of the immune system. While, together with magnesium, it helps to counteract muscle and mental fatigue.
Furthermore, vitamin B6 is essential for the proper functioning of the entire nervous system. It is useful in myelin formation, the sheath that covers neurons. Essential for serotonin and noradrenaline synthesis, it regulates sleep, mood, sense of hunger, and the ability to focus and maintain memory. It also plays an important role in the brain development of the fetus.
Vitamin B6 Dosage And Deficiency
The recommended daily intake varies according to age, sex, and condition: from 0.4 mg for newborns to 2 mg for breastfeeding women. For adults, the recommended daily intake is on average 1.3-1.4 mg. After 65 years old, it rises to 1.5 mg per day for men and 1.7 mg per day for women. In case of deficiency, before integrating vitamin B6, it is good to ask your doctor for advice to avoid overdosing, which can be as harmful as a deficiency.
If you follow a varied and balanced diet, it is difficult to risk vitamin B6 deficiencies, since it is present in many foods (even if its molecular form and bioavailability vary from food to food). Cases of a vitamin B6 deficiency can be connected to specific diseases (for example intestinal malabsorption), food allergies or intolerances, drastic diets (like poorly planned vegan diets), drug intake, alcohol abuse, and smoking. In the case of vitamin B6 deficiency, symptoms can vary from the skin and mucous membrane problems, lip cuts, nausea, vomiting, muscle weakness, depression, irritability, and neurological disorders.
Foods Rich In Vitamin B6
The main sources of vitamin B6 are foods of animal origin, which mainly contain pyridoxal and pyridoxamine, and they are more bioavailable. B6 is mainly found in red meat, poultry, and pork, especially in the liver. It is also present in fish (tuna and salmon) and shellfish (shrimp). Vitamin B6 is also found in eggs, milk, and dairy products. Foods of plant origin, on the other hand, mainly contain pyridoxine, especially whole grains (wheat, rice, etc.), legumes (chickpeas and lentils), green beans, potatoes, and cauliflower. Rich in vitamin B6 is nuts (walnuts, hazelnuts, almonds, pistachios, etc.). Avocados and bananas have a good vitamin B6 content. Other sources are wheat germ and brewer’s yeast.
How To Consume Food Containing Vitamin B6
Vitamin B6, unlike others, is heat stable (so it does not degrade with cooking). However, since it is water-soluble, it is better to steam foods that contain it or cook them with very little water, which is reabsorbed, or with water used to prepare broths or other dishes. Furthermore, nutritionists recommend not to freeze food (which subtracts up to 77% of vitamin B6), limiting the consumption of canned foods, and paying particular attention to conservation. The general rule is always the same: eat fresh and seasonal food, freshly prepared.
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https://ods.od.nih.gov/factsheets/list-VitaminsMinerals/ (last viewed 02/07/2022)
https://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/ (last viewed 02/07/2022)