Effects of Vitamins B6 and B12 on the Nervous System and Energy

B vitamins are water-soluble vitamins that are vital for the proper functioning of the body. Vitamins B6 (pyridoxine) and B12 (cobalamin) are particularly notable for their essential role in nervous system health, energy metabolism and immune function. These vitamins are essential micronutrients that the body cannot produce and must be obtained through food. This comprehensive informative content details the definition, biochemical composition, effects on the body, uses, side effects, dosage information and storage conditions of vitamins B6 and B12 based on scientific sources.

Vitamin B6 (Pyridoxine)

Definition and Biochemical Composition

Vitamin B6is found in three main forms, pyridoxine, pyridoxal and pyridoxamine. The active form in the body pyridoxal 5′-phosphate (PLP)and functions as a coenzyme in more than 100 enzymatic reactions. PLP acts as a coenzyme in more than 100 enzymatic reactions and plays a critical role in amino acid metabolism, neurotransmitter synthesis and glycogen breakdown. As it is a water-soluble vitamin, it is not stored in the body and must be taken regularly with food.

Effects on Body Functions

1. Nervous System Health: PLP is essential for the synthesis of neurotransmitters such as serotonin (mood), norepinephrine (stress response) and dopamine (motivation and reward). It also surrounds nerve cells and accelerates nerve conduction. formation of the myelin sheathalso plays a role. B6 deficiency can lead to neurological symptoms such as neuropathy, convulsions, depression and irritability.
   • Research Example: A study by Hvas et al. (2004) showed that adequate vitamin B6 levels may support neurological function by lowering homocysteine levels. Homocysteine is an amino acid that can be toxic to the nervous system at high levels.
2. Energy Metabolism: Vitamin B6 plays a key role in the conversion of proteins, carbohydrates and fats into energy. In particular, PLP is required for the activity of enzymes involved in the breakdown of glycogen (a stored form of glucose) into energy. This is important for physical performance and overall energy levels.
3. Immune Functions: Vitamin B6 plays a critical role in the production and activity of immune cells such as lymphocytes and cytokines. Inadequate B6 intake can weaken the immune response and reduce defense against infections.
   • Research Example: A review by Mastroiacovo et al. (2013) noted that vitamin B6 deficiency may suppress the immune system and increase the risk of infection.
4. Cardiovascular Health: Vitamin B6 helps control blood homocysteine levels by acting as a coenzyme in the conversion of homocysteine to methionine. High homocysteine levels are a risk factor for heart disease and stroke. B6 can reduce this risk by working together with B12 and folate.
   • Research Example: A meta-analysis by Eikelboom et al. (2006) showed that B vitamin supplements (including B6) may reduce the risk of cardiovascular events by lowering homocysteine levels, but the impact on clinical outcomes is controversial.
5. Inflammation Vitamin B6 deficiency has been associated with an increase in inflammatory markers. Adequate levels of B6 may help reduce chronic inflammation, which may contribute to the management of inflammatory conditions such as arthritis.
6. Physical Performance: Due to its role in energy metabolism, vitamin B6 supports the energy production of muscles during physical activity. It is also involved in hemoglobin synthesis, facilitating oxygen transport, which is important for endurance and performance.
7. Reproductive Health: Vitamin B6 may play a role in hormone balancing and alleviating symptoms of premenstrual syndrome (PMS), especially in women. It is also important for fetal brain development during pregnancy.

Areas of Use

• Dietary Supplements: It is used to overcome B6 deficiency or for general health.
• PMS and Neuropathy Treatment: It can be used to relieve the symptoms of these conditions under the supervision of a doctor.
• Morning sickness It may be recommended in some cases for morning sickness during pregnancy.

Side Effects

Vitamin B6 is generally safe at recommended doses. However, extremely high doses (usually over 100 mg/day and for prolonged periods) can cause serious side effects such as neuropathy (nerve damage), loss of balance and skin lesions.

Dosage Information

• Recommended Daily Allowance (RDA):
  • Adult Men (19-50 years): 1.3 mg/day
  • Adult Women (19-50 years): 1.3 mg/day
  • Pregnant Women 1.9 mg/day
  • Breastfeeding Women 2.0 mg/day
• Tolerable Upper Intake Limit (UL): 100 mg/day for adults. Doses exceeding this limit increase the risk of side effects.

Storage Conditions

Vitamin B6 supplements should be stored in the original packaging in a cool, dry place away from moisture, light and excessive heat.

 

Vitamin B12 (Cobalamin)

Definition and Biochemical Composition

Vitamin B12 or cobalaminis the only water-soluble vitamin with a complex structure containing cobalt atoms. There are two main active forms in the body: methylcobalamin and adenosylcobalamin. B12 is critical for DNA synthesis, red blood cell formation and nervous system health. It does not occur naturally in plant foods; it is mainly taken through animal products (meat, milk, eggs) and supplements. For absorption, it requires a protein called "intrinsic factor", which is produced in the stomach.

Effects on Body Functions

1. Nervous System Health: Vitamin B12 is a vitamin that protects nerve cells synthesis and maintenance of the myelin sheath is essential for the nervous system. It also contributes to the production of neurotransmitters important for the nervous system. B12 deficiency can lead to serious neurological and psychiatric symptoms such as peripheral neuropathy (numbness and tingling in the hands and feet), memory loss, difficulty concentrating, balance problems and depression.
   • Research Example: A review by Wolters et al. (2018) highlighted that B12 deficiency is associated with cognitive dysfunction and neurodegenerative diseases and the potential of supplementation in the prevention and treatment of these conditions.
2. Energy Metabolism: Vitamin B12 is involved in the conversion of fatty acids and amino acids into energy. It is involved in some stages of the Krebs cycle, which is critical for cellular energy production (ATP synthesis). B12 deficiency can cause lack of energy, fatigue and chronic exhaustion.
3. Red Blood Cell Formation: Vitamin B12 is essential for DNA synthesis, which in turn is critical for the proper maturation of rapidly dividing cells, especially red blood cells (erythrocytes). B12 deficiency is characterized by the production of large, abnormal red blood cells and reduced oxygen-carrying capacity. megaloblastic anemia leads to
   • Research Example: A review by Stabler and Allen (2004) detailed how B12 and folate deficiencies lead to megaloblastic anemia.
4. Immune Functions: Vitamin B12 is essential for the proper functioning of immune cells (especially lymphocytes and natural killer cells). It may increase resistance to infections by playing a role in regulating the immune response. B12 deficiency can lead to impaired immune function.
5. Cardiovascular Health: Together with B12, B6 and folate, it is involved in homocysteine metabolism, converting homocysteine to methionine. High homocysteine levels increase the risk of atherosclerosis and heart attack/stroke. B12 supplementation may reduce this risk by lowering homocysteine levels.
   • Research Example: A meta-analysis by Wang et al. (2018) found that B12 supplementation was effective in lowering homocysteine levels, which may provide a benefit for cardiovascular risk.
6. Physical Performance: B12 is important for physical performance because of its role in energy production and the formation of oxygen-carrying red blood cells. Individuals with B12 deficiency may experience fatigue, shortness of breath and muscle weakness, which negatively affects physical performance.
7. Reproductive Health: Vitamin B12 is critical for reproductive health due to its role in cell division and DNA synthesis. Adequate levels of B12 are required for sperm production and quality, and for egg development and implantation in women. B12 deficiency can lead to fertility problems and is important for fetal development during pregnancy.
   • Research Example: A review by Gaskins and Chavarro (2018) examined the effects of B12 and other B vitamins on fertility.

Areas of Use

• Treatment of Megaloblastic Anemia: It is the most common area of use.
• B12 Deficiency: It is mainly used as a supplement for vegans and vegetarians, the elderly (due to absorption problems), people who have undergone gastric surgery and those with chronic stomach conditions (e.g. atrophic gastritis, pernicious anemia).
• Neuropathy and Neurologic Symptoms: In the treatment of neurological symptoms due to B12 deficiency.
• Energy and Fatigue: To increase energy levels in people with B12 deficiency.

Side Effects

Since vitamin B12 is a water-soluble vitamin, it is generally considered safe even in excessive doses. There is no known upper intake limit. However, very high doses may rarely cause mild side effects such as diarrhea, itching or allergic reactions.

Dosage Information

• Recommended Daily Allowance (RDA):
  • Adult Men and Women (19 years and older): 2.4 mcg/day
  • Pregnant Women 2.6 mcg/day
  • Breastfeeding Women 2.8 mcg/day
• Supplement Dosages: For people with B12 deficiency, much higher doses (e.g. 500 mcg, 1000 mcg or even injections) can be used according to the doctor's recommendation. For vegans or vegetarians, doses of 25-100 mcg daily or 1000 mcg weekly may be recommended.

Storage Conditions

Vitamin B12 supplements should be stored in the original packaging in a cool, dry place away from light, moisture and excessive heat. Light in particular can cause vitamin B12 to deteriorate.

Sources

• Eikelboom, J. W., Hankey, G. J., & Anand, S. S. (2006). Homocysteine and cardiovascular disease: a critical review of the evidence. Annals of Internal Medicine, 145(2), 115-121.
• Gaskins, A. J., & Chavarro, J. E. (2018). Diet and fertility: a review. American Journal of Obstetrics and Gynecology, 218(4), 378-384.
• Hvas, A. M., Juul, S., & Nexø, E. (2004). Vitamin B6 status is associated with concentrations of homocysteine and methylmalonic acid in healthy individuals. European Journal of Clinical Nutrition, 58(2), 246-250.
• Mastroiacovo, P., Muto, V., & Fiore, G. (2013). Role of B vitamins in immunity. European Journal of Clinical Nutrition, 67(S1), S1-S5.
• Stabler, S. P., & Allen, R. H. (2004). Vitamin B12 deficiency as a cause of anemia. Annual Review of Medicine, 55, 549-563.
• Wang, L., Zhang, H., & Ma, P. (2018). The effect of vitamin B12 supplementation on homocysteine levels: A meta-analysis of randomized controlled trials. Nutrients, 10(10), 1530.

Wolters, M., Strohle, A., & Hahn, A. (2018). Vitamin B12 and brain health. Journal of Clinical Biochemistry and Nutrition, 62(1), 1-13.