These vitamins stimulate the production of neurotransmitters, promoting brain health (1). B-complex vitamins work through a simple mechanism. They also help maintain a healthy heart and immunity. In addition, b vitamins replenish various energy reserves in the body. This article discusses the benefits of the vitamin B complex, its richest dietary sources, common deficiency, and overdose symptoms. Take a look.
What Is The Vitamin B-Complex?
This vitamin group consists of eight vitamins:
B1 (Thiamine) B2 (Riboflavin) B3 (Niacin) B5 (Pantothenic acid) B6 (Pyridoxine) B7 (Biotin) B9 (Folate/Folic acid) B12 (Cobalamin)
These vitamins are most commonly found in everyday foods like seeds, meat, eggs, and vegetables (2). Each of these B vitamins has a specific benefit. In the following section, we will delve into the health benefits these nutrients offer.
What Are The Health Benefits Of B Vitamins?
B vitamins promote nerve health, thereby possibly improving brain function. They also boost heart health and immunity. Studies show that folate (vitamin B9) helps prevent birth defects during pregnancy.
1. May Promote Brain Health
B vitamins have been found to impact the central nervous system. More specifically, vitamins B6, B12, and folate have been linked to better cognitive health in the elderly (3). Individuals dealing with dementia were also found to have lower serum levels of B vitamins (especially folate and vitamin B12) (3). In another study, higher concentrations of vitamin B6 were found to have better effects on an individual’s memory (4). Folic acid and vitamin B12 may also aid depression treatment. Subjects with depressive tendencies were found to have lower levels of these two vitamins. Low serum folate levels are also found in patients with frequent mood disorders (5). Interestingly, countries with a high folate intake (Hong Kong and Taiwan) were found to have lower rates of major depression among their populations (5). B vitamins were also found to relieve anxiety and stress in certain workplace populations (6).
2. May Boost Nerve Function
Vitamin B12 has been linked to nerve regeneration. In rat studies, this vitamin was found to promote nerve regeneration in the event of peripheral nerve injury (7). Vitamin B12 also scavenges the reactive oxygen species. It has an anti-apoptotic and anti-necrotic (preventing the early death of cells) effect on the brain’s neurons. It even increases the regeneration of axons (7). Vitamin B12 is responsible for the improved function of nerve cells as well as their development (8). A deficiency in vitamin B12 can also lead to neuropathy or nerve damage. The vitamin also preserves the myelin sheath, which is the protective covering around the body’s nerves (9).
3. May Improve Cardiovascular Health
B vitamins help replenish various energy stores in the body. A deficiency in these vitamins can lead to reduced energy stores, which have been linked to myocardial dysfunction in patients with heart failure (10). Folic acid and vitamin B12 were found to have potential as heart disease treatments. While the former lowered homocysteine levels by 25 percent, the addition of the latter further lowered the levels by another 7 percent (11). Homocysteine is an amino acid occurring in the body, high levels of which have been linked to heart disease (11). Deficiency of vitamin B1 can lead to beriberi, a disease characterized by inflammation of the nerves and subsequent heart failure (12).
4. May Boost Immunity
The group of B vitamins has been identified as those that keep the immune system healthy (13). Certain animal studies also show that a deficiency of vitamin B6 may lead to undesirable changes to immune responses (14). However, more research on humans is warranted in this regard. Folate may also boost immunity, although we need more research at the moment. Folate plays a role in the process of production and repair of DNA and may have an impact on the immune system. Though folate deficiency was found to impair immunity in animals, similar effects are yet to be observed in humans (15).
5. May Help Treat Anemia
B vitamins are known to treat different forms of anemia. While folate and vitamin B12 can treat and prevent megaloblastic anemia (characterized by very large red blood cells and decrease in their number), vitamin B6 can treat sideroblastic anemia (characterized by the production of ringed blood cells instead of healthy red blood cells) (16). Vitamin B12 is critical for making red blood cells, which, in turn, carry oxygen to all parts of the body. A deficiency of vitamin B12 can cause the most common form of anemia, called pernicious anemia (characterized by a lack of enough healthy red blood cells) (17).
6. May Promote Eyesight
A deficiency in B-complex vitamins was linked to a defective vision. In a study carried out on school children, supplementation with B-complex vitamins was noted to improve their visual acuity (18). A deficiency of vitamin B12 may also lead to optic neuropathy. In a study involving an elderly male with decreased central vision (who was deficient in vitamin B12), supplementation of vitamin B12 was found to improve the condition (19). In another study, a combination of vitamins B6, B12, and folate was found to reduce the development of age-related macular degeneration over a period of seven years (20).
7. May Aid Digestive Health
There is some research stating that dexpanthenol, a derivative of vitamin B5 (pantothenic acid), may ease constipation (21). B vitamins have been found to have various benefits on the digestive system. Vitamin B12 deficiency was observed in several cases of liver diseases, including cirrhosis and hepatitis. It also may have a role to play in reducing the severity of stomach ulcers (and even canker sores) (22). In patients with irritable bowel syndrome, supplementation with vitamin B1 over 20 days reduced most of the symptoms, including fatigue (23). Vitamins B6, B9, and B12 were found to help prevent gastrointestinal cancer. In animal studies, vitamin B6 was found to prevent oxidative stress, thereby potentially combating colorectal cancer (24). Dietary folate may also help prevent pancreatic cancer (25).
8. May Improve Hormonal Health
B-complex vitamins are involved in the metabolism and activity of estrogen (26). Vitamin B6 has been linked to the regulation of anterior pituitary hormones (27). However, research is limited here. More scientific evidence is warranted.
9. May Help Relieve Migraines
Vitamin B2 supplementation was found to relieve migraines in both adults and children. The nutrient may reduce the frequency and duration of migraine attacks with no adverse effects (28). Other sources also quote vitamin B2 to be effective in treating migraine headaches (29). The mechanism behind how this vitamin works to treat migraines is still unclear, and more research is warranted.
10. Can Promote Healthy Pregnancy
Folate (vitamin B9) could be the most important B vitamin to be taken during pregnancy. The nutrient is known to prevent birth defects in infants (30). As per the World Health Organization, vitamin B6 also plays a major role during pregnancy. It was found to prevent pre-eclampsia (a dangerous pregnancy complication accompanied by very high blood pressure) and preterm birth (31). Maternal supplementation with vitamin B12 during pregnancy was found to cut the risk of B12 deficiency in the infant, in addition to further promoting its health (32).
11. May Promote Wound Healing
In studies conducted on diabetic mice, B vitamins were found to improve wound healing (33). In another study, B vitamins (along with vitamin C) were found to influence human keratinocytes and fibroblasts positively. This way, the vitamins can promote the wound healing process (34).
12. May Help Relieve Symptoms Of Premenstrual Syndrome
High intake of vitamins B1 and B2 was found to reduce the risk of premenstrual syndrome, especially when the vitamins came from natural food sources (35). In another study, intake of vitamin B6 (up to 100 mg per day) was found to treat premenstrual syndrome, including premenstrual depression (36). These are the many benefits of the B-complex vitamins. As discussed, they have several roles to play in the human body system. Each of those B vitamins serves a specific purpose. Though B vitamin deficiency could be rare, it is important to understand which foods offer most of those vitamins.
What Are The Richest Sources Of B Vitamins?
Here we have collated the top 10 foods that contain most of the B-complex vitamins. *Recommended Daily Allowance Source: US National Library of Medicine *The values correspond to the daily value of a particular nutrient that the food source meets. Including these foods in your daily diet should take care of your B-vitamin needs. This way, you would rarely become deficient in B-complex vitamins. But, the question is, how would you know if you are deficient?
What Are The Symptoms Of A Deficiency Of B-Complex Vitamins?
Following are the symptoms of a B-vitamin deficiency. If you experience any of these, please visit your doctor:
Weakness Extreme fatigue Confusion Tingling in the feet and hands Nausea Anemia Skin rashes Abdominal cramps
Your doctor may also recommend a supplement. Are supplements required?
A Note On B Vitamin Supplements
Whether these supplements are necessary or not depends on a number of factors. Most people should be able to meet the required amounts of B vitamins by following a balanced diet plan. However, pregnant women, vegetarians, vegans, older adults, and those who have undergone gastric surgeries may need to take supplements. They may need to take vitamin B12, along with other B-complex vitamins. The combination depends on the person. During pregnancy, there is a higher demand for B vitamins (especially folate and vitamin B12) (37). Studies show that about 30% of older adults may not be able to properly absorb vitamin B12 as they do not produce enough stomach acid required for the absorption (38). Vegetarians and vegans may also need to take supplements as their diet may not include all of the foods rich in B vitamins (39). Even those with certain medical conditions might need to take B vitamin supplements. These include:
Those with celiac disease (40) Those with inflammatory bowel disease (41) Those with hypothyroidism (42) Those undergoing cancer treatment (43) Those diagnosed with chronic alcoholism (44) Those who have undergone gastric bypass surgery (45)
What Are The Symptoms Of An Overdose Of B-Complex Vitamins?
B vitamins are water-soluble. The vitamins are not stored in your body but are excreted daily. Hence, it is highly unlikely you may overdose on B-complex vitamins. However, it is important to know the symptoms of an overdose. These may include the following:
Blurry vision Abdominal cramps Nausea Diarrhea Increased urination Excessive thirst
What is the best time to take a vitamin B-complex supplement? If you often experience symptoms like fatigue, confusion, nausea, anemia, and abdominal cramps, you may be deficient in vitamin B-complex. Consult a doctor immediately who can prescribe you certain supplements. Taking B vitamins after waking up could be the best time. Taking them on an empty stomach may improve their absorption. Check with your doctor, though. Does vitamin B-complex make you gain weight? No, taking vitamin B-complex supplements will not make you gain weight. Also, there is no information if these vitamins can help you lose weight. Most probably, they may not. Do B-complex vitamins boost energy? There is no research stating that taking B-complex vitamins can boost your energy levels. They definitely are not stimulants like caffeine. Is it okay to take B complex every day? Yes, you can do vitamin B complex under the supervision of your doctor. However, excess consumption of them might result in adverse side effects. Is it better to take B12 or B complex? This depends on your doctor’s recommendation and what your body requires. Consult your doctor about which vitamin B is required and the right dosage. Does B complex make you sleepy? Studies indicate that vitamin B12 aids in melatonin production which regulates your circadian rhythms (your body’s 24-hour internal clock) and aids in sleep (46) . How long does it take for vitamin B complex to work? According to anecdotal data, it may take up to 2 weeks to feel the complete effects and benefits of vitamin B complex. Is B complex good for hair? Yes, hair loss has been linked to a deficiency in vitamins B2 (riboflavin), B7 (biotin), b9 (folate), and B12. They boost red blood cell production which helps nourish your hair follicles and aid in hair development (47). Is it OK to take B12 and B complex together? Whether you should take B12 and B complex together relies on your doctor’s advice and what your body needs. Anecdotal evidence suggests that combining vitamin B12 and B complex is generally considered safe. Does B complex cause weight gain? According to research, excessive consumption of Vitamin B may stimulate appetite and cause weight gain (48). Sources
B Vitamins and the Brain: Mechanisms, Dose and Efficacy–A Review, Nutrients, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pubmed/26828517 Vitamins of the B Complex, United States Department of Agriculture, National Agricultural Library.https://naldc.nal.usda.gov/download/IND43861414/PDF B Vitamins, Cognition, and Aging: A Review, The Journals of Gerontology, Oxford Academic Journals.https://academic.oup.com/psychsocgerontology/article/56/6/P327/610645#10164417 Relations of vitamin B-12, vitamin B-6, folate, and homocysteine to cognitive performance in the Normative Association between intake of B vitamins and cognitive function in elderly Koreans with cognitive impairment.https://pubmed.ncbi.nlm.nih.gov/25516359/ Treatment of depression: time to consider folic acid and vitamin B12, Journal of Psychopharmacology, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pubmed/15671130 Reducing occupational stress with a B-vitamin focussed intervention: a randomized clinical trial: study protocol, Nutrition Journal, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4290459/ Vitamin B complex and vitamin B12 levels after peripheral nerve injury, Neural Regeneration Research, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4904479/ B Vitamins, Harvard School of Public Health.https://www.hsph.harvard.edu/nutritionsource/vitamins/vitamin-b/ Vitamin B-12, University of Rochester Medical Center.https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=19&contentid=VitaminB-12 The role of B vitamins in the management of heart failure, Nutrition in Clinical Practice, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pubmed/22516940 Folic acid, vitamin B12 show potential as heart disease treatments, University of California San Francisco.https://www.ucsf.edu/news/2001/08/4932/folic-acid-vitamin-b12-show-potential-heart-disease-treatments Vitamin B1 Thiamine Deficiency (Beriberi), National Center for Biotechnology Information.https://www.ncbi.nlm.nih.gov/books/NBK537204/ Vitamins and minerals that affect the immune system, US Department of Veteran Affairs.https://www.hiv.va.gov/patient/daily/diet/vitamin-mineral-chart-table1.asp How to boost your immune system, Harvard Medical School.https://www.health.harvard.edu/staying-healthy/how-to-boost-your-immune-system Folate status and the immune system. Progress in Food & Nutrition Science, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pubmed/1887065 The role of vitamins in the prevention and control of anaemia, Public Health Nutrition, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pubmed/10948381 Vitamin B12 Deficiency Anemia, Johns Hopkins Medicine.https://www.hopkinsmedicine.org/health/conditions-and-diseases/vitamin-b12-deficiency-anemia Vitamin B-complex deficiency and visual acuity, The British Journal of Nutrition, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pubmed/420756 Optic neuropathy in vitamin B12 deficiency, European Journal of Internal Medicine, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pubmed/16198909 Folic Acid, Vitamin B6, and Vitamin B12 in Combination and Age-related Macular Degeneration in a Randomized Trial of Women, Archives of Internal Medicine, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2648137/ Dexpanthenol (Ro 01-4709) in the treatment of constipation, Acta vitaminologica et enzymologica, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pubmed/6751051 Role of vitamins in gastrointestinal diseases, World Journal of Gastroenterology, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4419060/#__sec8title Thiamine and fatigue in inflammatory bowel diseases: an open-label pilot study, Journal of Alternative and Complementary Medicine, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pubmed/23379830/ Vitamin B6 and colorectal cancer: current evidence and future directions, World Journal of Gastroenterology, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pubmed/23467420/ Folate intake and pancreatic cancer risk: an overall and dose-response meta-analysis, Public Health, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pubmed/23769243/ Vitamin Deficiencies and Estrogen Activity, Nutrition Reviews, Oxford Academic Journals.https://academic.oup.com/nutritionreviews/article-abstract/3/10/308/1908359?redirectedFrom=PDF The interactions between vitamin B6 and hormones, Vitamins and Hormones, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pubmed/217175 Supplementation with Riboflavin (Vitamin B2) for Migraine Prophylaxis in Adults and Children: A Review, International Journal for Vitamin and Nutrition Research, Hogrefe.https://econtent.hogrefe.com/doi/abs/10.1024/0300-9831/a000225 Headache, Health University of Utah.https://healthcare.utah.edu/neurosciences/pdfs/headache-guide.pdf Folate in pregnancy, Journal of Pediatric Neurosciences, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3519088/ Pyridoxine (vitamin B6) supplementation in pregnancyhttps://pubmed.ncbi.nlm.nih.gov/16625530/ Vitamin B-12 Supplementation during Pregnancy and Early Lactation Increases Maternal, Breast Milk, and Infant Measures of Vitamin B-12 Status, The Journal of Nutrition, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3985831/ The effect of B vitamin supplementation on wound healing in type 2 diabetic mice, Journal of Clinical Biochemistry and Nutrition, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4706087/ Effects of Vitamin B Complex and Vitamin C on Human Skin Cells, Advances in Skin and Wound Care.https://journals.lww.com/aswcjournal/Abstract/2018/05000/Effects_of_Vitamin_B_Complex_and_Vitamin_C_on.7.aspx Dietary B vitamin intake and incident premenstrual syndrome, The American Journal of Clinical Nutrition, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3076657/ Efficacy of vitamin B-6 in the treatment of premenstrual syndrome: systematic review, British Journal of Medicine, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC27878/ Vitamin B-12 and Perinatal Health, Advances in Nutrition, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4561829/ Vitamin B12 and older adults, Current Opinion in Clinical Nutrition and Metabolic Care, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5130103/ Vitamin B12 among Vegetarians: Status, Assessment and Supplementation, Nutrients, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5188422/ Vitamin and Mineral Deficiencies Are Highly Prevalent in Newly Diagnosed Celiac Disease Patients, Nutrients, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3820055/ Status of serum vitamin B12 and folate in patients with inflammatory bowel disease in China, Intestinal Research, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5323299/ Vitamin B12 deficiency common in primary hypothyroidism, The Journal of the Pakistan Medical Association, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pubmed/18655403 Functional vitamin B12 deficiency in advanced malignancy: implications for the management of neuropathy and neuropathic pain, Supportive Care in Cancer, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pubmed/27003903 Mechanisms of vitamin deficiencies in alcoholism, Alcoholism, Clinical and Experimental Research, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pubmed/3544907 Nutritional deficiencies after gastric bypass surgery, The Journal of the American Osteopathic Association, US National Library of Medicine, National Institutes of Health.https://www.ncbi.nlm.nih.gov/pubmed/19948694 The Effects of Magnesium – Melatonin – Vit B Complex Supplementation in Treatment of Insomnia. Djokic G, Vojvodić P, Korcok D, Agic A, Rankovic A, Djordjevic V, Vojvodic A, Vlaskovic-Jovicevic T, Peric-Hajzler Z, Matovic D, Vojvodic J, Sijan G, Wollina U, Tirant M, Thuong NV, Fioranelli M, Lotti T. Open Access Maced J Med Sci.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6910806/ The Role of Vitamins and Minerals in Hair Loss: A Review. Dermatol Ther (Heidelb). Almohanna HM, Ahmed AA, Tsatalis JP, Tosti A. 2019 Mar.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6380979/ Zhou SS, Zhou Y. Excess vitamin intake: An unrecognized risk factor for obesity. World J Diabetes. 2014 Feb 15;5(1):1-13. doi: 10.4239/wjd.v5.i1.1. PMID: 24567797; PMCID: PMC3932423.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3932423/
