Supplements The Benefits of B Complex Vitamins By Cathy Wong facebook twitter Cathy Wong is a nutritionist and wellness expert. Her work is regularly featured in media such as First For Women, Woman's World, and Natural Health. Learn about our editorial process Cathy Wong Fact checked by Fact checked by Sean Blackburn on May 22, 2020 linkedin Sean is a fact checker and researcher with experience in sociology and field research. Learn about our editorial process Sean Blackburn on May 22, 2020 Print Table of Contents View All B1 (Thiamine) B2 (Riboflavin) B3 (Niacin) B5 (Pantothenic Acid) B6 (Pyridoxine) B7 (Biotin) B9 (Folic Acid) B12 (Cobalamin) Uses Side Effects A B complex vitamin usually delivers eight of the B vitamins: B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), B9 (folic acid), and B12 (cobalamin). Found naturally in meat, leafy greens, dairy, beans, peas, and whole or fortified grains, B complex vitamins help your body make energy from the food you eat, form red blood cells, and play an essential role in certain bodily functions. Take a closer look at the benefits, signs of deficiency, and food sources for each of these B complex vitamins. Verywell / Joshua Seong B1 (Thiamine) Health Benefits Critical for the growth, development, and function of cells in the bodyHelps the body use carbohydrates from food to produce energyNeeded for the health of the brain, muscles, and nervous system Symptoms of Deficiency BeriberiCardiovascular symptomsFatigueIrritabilityShort-term memory lossWeaknessWeight loss Food Sources Common food sources of vitamin B1 include fortified breakfast cereal, enriched and whole-grain products (bread, breakfast cereals, rice, noodles, and flour), wheat germ, pork, trout, black beans, mussels, and tuna. B2 (Riboflavin) Health Benefits Keeps the eyes, nervous system, and skin healthyHelps convert food into energyNeeded for red blood cell production and growthWorks with other B vitamins (helps convert B6 into a usable form and aids in niacin production) Symptoms of Deficiency Cracks at the corners of the mouthHair lossSensitivity to lightSkin disordersSore throatSwelling of the mouth and throatSwollen, cracked lips Food Sources Common food sources of vitamin B2 include milk and dairy products, fortified breakfast cereals, beef liver, clams, portobello mushrooms, almonds, and chicken. B3 (Niacin) Health Benefits Aids in the conversion of food into energyHelps enzymes in the body function properly by helping the body use other B vitamins and make and repair DNA (the genetic material found in all body cells)Helps with the function of the digestive and nervous systems and skinNeeded for the production of hormones, such as sex and stress hormones Symptoms of Deficiency Canker soresDepressionDigestive problemsFatigueInflamed skinPellagraPoor circulationVomiting Food Sources Common food sources of vitamin B3 include eggs, fish, fortified bread and cereal, rice, nuts, milk and dairy, chicken, beef, turkey, lamb, organ meats, peanuts. Niacin Health Benefits and Uses B5 (Pantothenic Acid) Health Benefits Breaks down fats and carbohydrates for energyHelps the body use other vitamins, such as riboflavinPlays a role in the production of sex and stress hormones in the adrenal glands and neurotransmittersVitamin B5 is needed for the production of red blood cells and cholesterol Symptoms of Deficiency Burning feetDepressionFatigueInsomniaIrritabilityStomach painsUpper respiratory tract infectionsVomiting Food Sources Common food sources of vitamin B5 include meat, avocado, broccoli, kale, eggs, milk, mushrooms, fortified cereals, organ meats, poultry, potatoes, and legumes. Benefits of Vitamin B5 B6 (Pyridoxine) Health Benefits Involved in immune function and brain development and functionNeeded by the body to use and store protein and carbohydrates from food (in the form of glycogen, stored energy in the muscles and liver)Required for more than 100 enzyme reactions in the body. It aids in the formation of hemoglobin (a substance in red blood cells that carries oxygen through the blood) and neurotransmitters and hormones that influence mood and regulate the body's clock Symptoms of Deficiency DepressionDifficulty concentratingIrritabilityMuscle weaknessNervousnessShort-term memory loss Food Sources Common food sources of vitamin B6 include chickpeas, beef liver, tuna, salmon, chicken breast, fortified breakfast cereal, potatoes, turkey, fruits (except citrus), and beef. Vitamin B6 Uses and Sources B7 (Biotin) Health Benefits Helps the body convert the fats, carbohydrates, and proteins in the food that you eat into energyNeeded to make fatty acidsPromotes growth and bone and hair health Symptoms of Deficiency Brittle nailsDry eyesHair thinning or lossMuscle painSkin rashes around the eyes, nose, mouth, or other mucous membranes Food Sources Common food sources of vitamin B7 include beef liver, egg yolk, wheat germ, pork, beef, sunflower seeds, sweet potato, almonds, whole-grain foods, sardines, spinach, and broccoli. Biotin Health Benefits and Common Uses B9 (Folic Acid) Health Benefits Helps your body make red blood cellsNeeded to help cells make and maintain DNAReduces the risk of birth defects in the brain and spine, such as spina bifida Symptoms of Deficiency DiarrheaForgetfulnessGingivitisIrritabilityLoss of appetitePoor growthShortness of breathTongue inflammation Food Sources Common food sources of vitamin B9 (folate) include spinach, beef liver, broccoli, Brussels sprouts, beans and legumes, asparagus, orange juice, peanuts, avocado, dark leafy greens, fortified cereals, and salmon. Folate and Folic Acid B12 (Cobalamin) Health Benefits Helps keep the nervous system and red blood cells healthyImportant for protein metabolismRequired for the formation of red blood cells and DNA Symptoms of Deficiency ConstipationFatigueLack of appetiteMegaloblastic anemiaNerve damageNumbness and tingling in the fingers and toesWeaknessWeight loss Food Sources Common food sources of vitamin B12 are found primarily in animal foods, such as beef liver (and other organ meats), clams and other shellfish, beef, chicken, fish, eggs, milk, and other dairy products, and some fortified cereals. Vitamin B12 Uses, Side Effects Uses With a key role in converting food into fuel, proponents claim that B complex vitamins can help with a variety of conditions, including anxiety, depression, heart disease, and premenstrual syndrome (PMS). In addition, some people take a vitamin B complex to increase energy, enhance mood, improve memory, boost skin and hair health and stimulate the immune system. While most people who eat a varied diet get enough B vitamins from food, some people are at an increased risk of deficiency, particularly those who are over the age of 50, take antacid medication, or have celiac disease, Crohn's disease, gastritis, or other digestive disorders. If you have had stomach or weight loss surgery, drink alcohol regularly, or follow a vegetarian or vegan diet, you may be more prone to a deficiency. Pregnant and breastfeeding women may need more vitamins B6, B12, and folic acid. B Complex Side Effects Although B complex supplements are water-soluble and do not stay in the body for long, large doses of the vitamins in supplement form can cause certain side effects: B3 (niacin): Skin flushing or pain, elevated blood sugar levels, and liver toxicityB6 (pyridoxine): B6 may cause nerve damage, skin lesions, worsening of kidney function, and increased risk of heart attack, stroke, and death in people with diabetes and advanced kidney disease. Studies have associated high doses of vitamin B6 with a slightly increased risk of hip fracture and increased risk of lung cancer (when taken with vitamin B12).B9 (folic acid): Vitamin B6 can result in kidney damage, increased insulin resistance in offspring, lower natural killer cell activity in older women, and may be associated with increased risk of some cancers. It also may mask the diagnosis of a vitamin B12 deficiency.B12 (cobalamin): Vitamin B12 has been found to speed the decline in kidney function and increase the risk of cardiovascular events in people with impaired kidney function. High doses of vitamin B12 taken with folic acid have been associated with a greater risk of cancer and mortality, along with acne and rosacea in some people. There is a daily tolerable intake level (UL) for each B vitamin, which is above what most people need. Getting more than the UL increases your chances of side effects. A Word From Verywell To stay healthy, most people can get what they need by eating a varied, balanced diet filled with delicious foods naturally rich in B vitamins, such as leafy greens, nuts, beans and legumes, whole grains, lean protein, mushrooms, and eggs. There isn't solid evidence to support taking excessive amounts of B vitamins if you're not deficient in them. If you're not getting enough of a B vitamin from your diet, taking a vitamin B supplement may be beneficial for some people. Deficiency in B vitamins can cause a number of symptoms, including tiredness, anemia, loss of appetite, depression, abdominal pain, muscle cramps, hair loss, and eczema. Just be sure to consult your health care provider to find out whether a B complex supplement is right for you (and if so, the appropriate amount considering the total daily amount you are getting from food and supplements). Was this page helpful? Thanks for your feedback! Get nutrition tips and advice to make healthy eating easier. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. NIH. Vitamin B12. Updated March 30, 2020. NIH. Niacin. Updated March 6, 2020. Meyer HE, Willett WC, Fung TT, Holvik K, Feskanich D. Association of high intakes of Vitamins B6 and B12 from food and supplements with risk of hip fracture among postmenopausal women in the nurses' health study. JAMA Netw Open. 2019;2(5):e193591. doi:10.1001/jamanetworkopen.2019.3591 NIH. Folate B9. Updated March 11, 2020. Oliai araghi S, Kiefte-de jong JC, Van dijk SC, et al. Folic acid and Vitamin B12 supplementation and the risk of cancer: Long-term follow-up of the B Vitamins for the prevention of osteoporotic fractures (B-PROOF) trial. Cancer Epidemiol Biomarkers Prev. 2019;28(2):275-282. doi:10.1158/1055-9965.EPI-17-1198 Brescoll J, Daveluy S. A review of vitamin B12 in dermatology. Am J Clin Dermatol. 2015;16(1):27-33. doi:10.1007/s40257-014-0107-3 Additional Reading NIH. Biotin. Updated February 19, 2020. NIH. Folate B9. Updated March 11, 2020. NIH. Niacin. Updated March 6, 2020. NIH. Pantothenic Acid. Updated March 2, 2020. NIH. Riboflavin. Updated March 6, 2020. NIH. Thiamin. Updated February 19, 2020. NIH. Vitamin B12. March 30, 2020. NIH. VItamin B6. Updated February 24, 2020. Afriyie-Gyawu E, Ifebi E, Ampofo-Yeboah A, Kyte B, Shrestha S, Zhang J. Serum folate levels and fatality among diabetic adults: A 15-y follow-up study of a national cohort. Nutrition. 2016 Apr;32(4):468-73. Kim SJ, Zuchniak A, Sohn KJ, et al. Plasma folate, vitamin B-6, and vitamin B-12 and breast cancer risk in BRCA1- and BRCA2-mutation carriers: a prospective study. Am J Clin Nutr. 2016 Sep;104(3):671-7. Tio M, Andrici J, Cox MR, Eslick GD. Folate intake and the risk of prostate cancer: a systematic review and meta-analysis. Prostate Cancer Prostatic Dis. 2014 Sep;17(3):213-9. Wang R, Zheng Y, Huang JY, Zhang AQ, Zhou YH, Wang JN. Folate intake, serum folate levels, and prostate cancer risk: a meta-analysis of prospective studies. BMC Public Health. 2014 Dec 29;14:1326.