If you’ve looked at a multivitamin or B complex label, you’ve come across vitamin B6 and vitamin B12, also known as pyridoxine and cobalamin, respectively. They’re two members of the water-soluble B vitamin family that are important for energy metabolism, skin health, red blood cell production, and more.
Although they commonly work as a team to support optimal body function, they each have separate roles in supporting various physiological and biological processes.
Right now, we’re taking an in-depth look at both vitamins and shedding light on their functions, recommended daily intake, deficiency signs and symptoms, and more.
Let’s get started.
What Are They?
Vitamin B6 and B12 are two of eight water-soluble B vitamins that play a host of essential roles in the body - and they also happen to be two of the most popular B vitamins.
Both nutrients exist naturally in many foods but can also be obtained in singular supplementation or as a B-complex. They are naturally stored in the liver, but because of their water-soluble nature, excess B6 is flushed out in the urine, so daily replenishment is essential to avoid deficiency.
Vitamin B6
Also known as pyridoxine, vitamin B6 is a water-soluble nutrient that plays a significant role in carbohydrates, protein, and fat metabolism, as well as the production of red blood cells and neurotransmitters 1. Vitamin B6 cannot be produced in the body and must be obtained through diet or supplementation.
We usually think of vitamin B6 as a single vitamin, but it’s a generic name for a group of six compounds called vitamers with B6 activity: Pyridoxine, pyridoxal, and pyridoxamine, and their respective 5’-phosphate esters. There are also two active coenzyme forms of B12: Pyridoxal 5’ phosphate (PLP) and pyridoxamine 5’ phosphate (PMP) 2, 3.
The vitamin B6 coenzymes are paramount for normal physiological function and are involved in over 100 enzyme reactions, primarily in protein, carbohydrates, and lipid metabolism. But to understand the extent of its importance, you also need to realize that it’s also critical for 1:
- Neurotransmitter synthesis
- Homocysteine metabolism
- Gluconeogenesis
- Glycogenolysis
- Immune function
- Hemoglobin formation
Although most people consume enough B6 through diet, some populations may have a higher risk of deficiency.
Vitamin B12
Vitamin B12, on the other hand, also called cobalamin, is another water-soluble B vitamin that’s naturally found in food, added to others, and widely available in supplementary form. It contains the mineral cobalt, which is why the B12 compounds are collectively referred to as “cobalamins” 2.
The two metabolically active forms of B12, the former of which is common in supplements, are methylcobalamin and 5-deoxyadenosylcobalamin, but you’ll also hydroxycobalamin and cyanocobalamin, which are biologically active after conversion to methylcobalamin or 5-deoxyadenosylcobalamin.
Vitamin B12 plays several important biological roles in body functions, especially in the development, myelination, and function of the central nervous system, red blood cell production, and DNA synthesis 4, 5. It also serves as a cofactor for two important enzymes: Methionine synthase and L-methylmalonyl-CoA mutase.
Methionine synthase is involved in the conversion of homocysteine methionine, which is required to form S-adenosylmethionine (SAM-e), a universal methyl donor essential for nearly 100 different substrates, including DNA, RNA, proteins, and lipids 5.
L-methylmalonyl-CoA mutase, on the other hand, converts L-methylmalonyl-CoA to succinyl-CoA, which is involved in the metabolism of propionate, a short-chain fatty acid.
But one of the unique things about B12 compared to all other B vitamins is its absorption pathway. Before B12 can be absorbed in the body, it must be released from the protein it’s bound to. Once the food reaches the stomach, it’s acted on by hydrochloric acid (stomach acid) and gastric protease and then binds to haptocorrin 1.
Once in the small intestine, B12 binds to a protein called intrinsic factor to create a B12-IF complex that can be absorbed in the latter portion of the ileum (small intestine). However, if B12 is already in its free form - as it is with most supplements - it doesn’t need to go through this process.
Here’s a rundown of what vitamin B12 is involved in:
- DNA production
- Nervous system development, myelination, and function
- Red blood cell formation
- Homocysteine conversion
Why Do You Need Them: Benefits Of Vitamin B6 And B12
Vitamin B6
As we mentioned, vitamin B6’s coenzymes PLP and PMP are essential for over 100 enzymatic reactions involved in various biochemical reactions, especially those involved in energy metabolism. But apart from energy production, here are some benefits of getting enough B6.
- May improve mood: Because of its role in producing several neurotransmitters - serotonin, dopamine, and gamma-aminobutyric acid - B6 may be essential in regulating mood 6, 7. It’s also required to convert homocysteine to methionine, and high blood homocysteine has been associated with depression and other psychiatric issues 8.
- Promotes cognitive health: Vitamin B6 serves as an essential coenzyme to reduce blood levels of homocysteine, which can, in turn, reduce the risk of brain disorders like Alzheimer’s 9, 10. Although the exact link between homocysteine and brain function isn’t clear, it is known that high homocysteine may have direct toxic effects on neurons of the central nervous system 11. One study of people with elevated homocysteine levels and mild cognitive impairment found that supplementation with high-dose B6, B12, and folate (B9) reduced homocysteine levels and mitigated wasting in some areas of the brain that are vulnerable to Alzheimer’s.
- Supports hemoglobin production: Iron deficiency is one of the most common nutrient deficiencies worldwide, and some research suggests that B6 can treat anemia because of its role in supporting hemoglobin production 12. Hemoglobin is a protein that transports oxygen to tissues, and low hemoglobin results in poor oxygen delivery and can lead to anemia. And studies have linked low B6 to anemia, especially in pregnant women 13.
- May treat PMS symptoms: Because of its role in neurotransmitter synthesis and mood regulation, B6 could help treat symptoms of PMS. One study found that premenopausal women taking 50 mg of vitamin B6 daily for three months saw improvement in PMS symptoms of depression, irritability, and tiredness by a whopping 69% 14.
- Supports heart health: People with low B6 levels may be at a higher risk of heart disease, likely because of the role of B6 in reducing homocysteine levels; elevated homocysteine is linked to several disease processes 15-17.
On top of these benefits, vitamin B6 may also be beneficial for:
- Preventing cancer
- Promoting eye health
- Treating rheumatoid-arthritis-induced inflammation
Vitamin B12
- May treat anemia: Vitamin B12 is essential for producing red blood cells, and a deficiency of B12 means your body can’t produce enough healthy blood cells to oxygenate the body, leading to a condition called vitamin B12-deficient anemia 18, 19. And because tissues aren’t properly oxygenated, it leads to symptoms like weakness and fatigue. A deficiency can even damage the heart and nervous system when severe enough. Supplementation effectively normalizes blood levels of B12 and reduces the risk of anemia.
- Boosts energy levels: If you’ve ever looked at an energy supplement, chances are you’ve seen vitamin B12 on the ingredient list. Although there’s little proof that B12 boosts energy, it’s thought that its role in red blood cell production and preventing anemia can enhance energy levels.
- Prevents birth defects: For pregnant women or those looking for kids in the future, B12 is essential. Along with folate (B9), vitamin B12 is needed for the growth and development of the central nervous system. A deficiency can cause cognitive and developmental delays, neural tube defects, impaired weight gain, and other adverse outcomes 20.
- May improve bone health: Although vitamin D and calcium are staples for bone health, studies suggest that through their links to homocysteine metabolism, vitamin B12 could be vital for supporting bone health and reducing the risk of osteoporosis or hip fractures 21. Research shows B12 has direct effects on osteoblast proliferation and formation (bone-building cells), and low B12 increases osteoclast (bone-breaking cells) activity 22.
On top of these benefits, B12 is also beneficial for:
- Regulating mood
- Heart health
- Skin, hair, and nail health
- Red blood cell production
Where To Find Them
Although vitamins B6 and B12 are widely available in all sorts of supplements, we have two go-to products: Performance Lab NutriGenesis Multi and Performance Lab Caffeine+.
Multi is a state-of-the-art multivitamin that combines 100+ RDI of 17+ high-quality bioidentical nutrients complexed cofactors for optimal absorption and bioactivities.
It’s pure and potent and supplies the most optimal form of B6 and B12 required for peak performance. Caffeine+, on the other hand, is a unique formulation of ingredients designed to provide peak stimulatory benefits without the side effects of conventional high-stim products.
It combines everything your body needs for energy - natural caffeine and B vitamins - and combines them with boosters and balancers for cleaner, longer-lasting energy without the risks.
But if you’re in the mood to boost your intake of B6 and B12 through diet, here’s where you can find them:
Vitamin B6
- Liver (beef, chicken)
- Salmon
- Tuna
- Poultry
- Chickpeas
- Dark leafy green vegetables
- Sweet potato
- Bananas
- Papaya
- Oranges
- Cantaloupe
- Dairy products (milk, cheese)
- Eggs
- Avocado
Vitamin B12
- Organ meats (liver, kidney, etc.)
- Clams
- Sardines
- Beef
- Fortified cereals
- Tuna
- Trout
- Salmon
- Nutritional yeast
- Milk and dairy products
- Eggs
Except for a few foods, B12 is primarily concentrated in animal products, so those following a plant-based diet should consider vitamin B12 supplementation.
References
- Hellmann H, Mooney S. Vitamin B6: a molecule for human health? 2010;15(1):442-459.
- Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes: Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: National Academy Press; 1998.
- McCormick D. Vitamin B6. In: Bowman B, Russell R, eds. Present Knowledge in Nutrition. 9th ed. Washington, DC: International Life Sciences Institute; 2006.
- Allen LH. Vitamin B-12. Adv Nutr. 2012;3(1):54-55.
- Stabler SP. Vitamin B12. In: Marriott BP, Birt DF, Stallings VA, Yates AA, eds. Present Knowledge in Nutrition. 11th ed. Washington, DC: Elsevier; 2020:257-71.
- Clayton PT. B6-responsive disorders: a model of vitamin dependency. J Inherit Metab Dis. 2006;29(2-3):317-326.
- Nutt DJ. Relationship of neurotransmitters to the symptoms of major depressive disorder. J Clin Psychiatry. 2008;69 Suppl E1:4-7.
- Folstein M, Liu T, Peter I, et al. The homocysteine hypothesis of depression ]. Am J Psychiatry. 2007;164(6):861-867.
- Seshadri S, Beiser A, Selhub J, et al. Plasma homocysteine as a risk factor for dementia and Alzheimer’s disease. N Engl J Med. 2002;346(7):476-483.
- Oulhaj A, Refsum H, Beaumont H, et al. Homocysteine as a predictor of cognitive decline in Alzheimer’s disease. Int J Geriatr Psychiatry. 2010;25(1):82-90.
- Malouf R, Grimley Evans J. The effect of vitamin B6 on cognition. Cochrane Database Syst Rev. 2003;(4):CD004393.
- Spinneker A, Sola R, Lemmen V, Castillo MJ, Pietrzik K, González-Gross M. Vitamin B6 status, deficiency and its consequences--an overview. Nutr Hosp. 2007;22(1):7-24.
- Hisano M, Suzuki R, Sago H, Murashima A, Yamaguchi K. Vitamin B6 deficiency and anemia in pregnancy. Eur J Clin Nutr. 2010;64(2):221-223.
- Doll H, Brown S, Thurston A, Vessey M. Pyridoxine (vitamin B6) and the premenstrual syndrome: a randomized crossover trial. J R Coll Gen Pract. 1989;39(326):364-368.
- Lin PT, Cheng CH, Liaw YP, Lee BJ, Lee TW, Huang YC. Low pyridoxal 5'-phosphate is associated with increased risk of coronary artery disease. 2006;22(11-12):1146-1151.
- Vermeulen EG, Stehouwer CD, Twisk JW, et al. Effect of homocysteine-lowering treatment with folic acid plus vitamin B6 on progression of subclinical atherosclerosis: a randomised, placebo-controlled trial. Lancet. 2000;355(9203):517-522.
- Endo N, Nishiyama K, Otsuka A, Kanouchi H, Taga M, Oka T. Antioxidant activity of vitamin B6 delays homocysteine-induced atherosclerosis in rats. Br J Nutr. 2006;95(6):1088-1093.
- Hannibal L, Lysne V, Bjørke-Monsen AL, et al. Biomarkers and Algorithms for the Diagnosis of Vitamin B12 Deficiency . Front Mol Biosci. 2016;3:27.
- Cavalcoli F, Zilli A, Conte D, Massironi S. Micronutrient deficiencies in patients with chronic atrophic autoimmune gastritis: A review. World J Gastroenterol. 2017;23(4):563-572.
- Behere RV, Deshmukh AS, Otiv S, Gupte MD, Yajnik CS. Maternal Vitamin B12 Status During Pregnancy and Its Association With Outcomes of Pregnancy and Health of the Offspring: A Systematic Review and Implications for Policy in India. Front Endocrinol (Lausanne). 2021;12:619176.
- Dai Z, Koh WP. B-vitamins and bone health--a review of the current evidence. 2015;7(5):3322-3346.
- Vaes BL, Lute C, Blom HJ, et al. Vitamin B(12) deficiency stimulates osteoclastogenesis via increased homocysteine and methylmalonic acid. Calcif Tissue Int. 2009;84(5):413-422.