Medically reviewed by Katelyn Hagerty, FNP
Written by Our Editorial Team
Last updated 5/17/2021
If you’ve searched for information about maintaining your hair, you might have seen B vitamins recommended as helpful tools for stimulating healthy hair growth.
There are eight different B-vitamins, which together are known as the vitamin B complex. These vitamins are widely available in nutritional supplements and offer a range of different benefits for your health and wellbeing.
But can B-complex vitamins contribute to hair growth? While vitamin B clearly plays a key role in the hair growth process, the scientific evidence is mixed when it comes to the effectiveness of B complex vitamins for hair growth.
Below, we’ve explained what vitamin B complex supplements are, as well as the eight different types of vitamin B that make up this group of vitamins.
We’ve also listed and discussed some of the major health benefits associated with the different forms of vitamin B, including the potential effects of B vitamins on hair growth.
Finally, we’ve explained what you can do if you’re starting to lose your hair and want to turn to vitamins, supplements and other treatments to restore hair growth.
We want you to walk away smarter. But if you’re only interested in the bottom line, here it is:
B vitamins offer countless health benefits. However, if you eat a balanced diet, you may not need to use a B-complex vitamin supplement.
There is some evidence that taking a biotin supplement can aid hair loss in men who are biotin deficient. However, biotin deficiency is uncommon.
Because B vitamins are water-soluble, your body eliminates any excess amount through your pee. As such, you’re not doing yourself any favors by taking massive quantities. An obvious indicator you’re overdoing it is bright yellow urine.
If you’re worried about your B-vitamin levels, consider adding a multivitamin supplement to your daily health routine. You’ll likely get more from this than from a vitamin B complex supplement.
While many people associate the term “vitamin B” with a single vitamin, the reality is that there are eight different B vitamins, each with their own important functions in your body.
The eight different B vitamins are thiamine (vitamin B1), riboflavin (vitamin B2), niacin (vitamin B3), pantothenic acid, vitamin B6, biotin (vitamin B7), folic acid (folate), and vitamin B12.
All of these vitamins are water-soluble and all play key roles in helping your body to metabolize important nutrients, such as proteins, fats and carbohydrates.
Thiamine, or vitamin B1, is an important vitamin that plays a key role in converting nutrients into usable energy. It’s an essential cofactor for several of the enzymes that metabolize glucose and amino acids.
Many whole grains, meats and fish products contain thiamine. Good food sources of this vitamin include enriched rice, fortified breakfast cereals, black beans, mussels, tuna, pork, beef, orange juice and sunflower seeds.
The Office of Dietary Supplements, part of the National Institutes of Health, recommends that all men aged 19 or above consume 1.2mg of thiamine per day.
Riboflavin, or vitamin B2, is an essential component of two major coenzymes involved in cellular function, energy production and metabolism.
It also assists your body to maintain normal levels of the amino acid homocysteine, which is used to create proteins.
You can find riboflavin in many whole grains and protein-rich foods, including beef liver, fortified breakfast cereals, oats, yoghurt, milk, clams, chicken breast, beef steak, mushrooms, almonds, certain types of cheese, salmon and quinoa.
The Office of Dietary Supplements recommends that men aged 19 and older should consume a dietary intake of 1.3mg of riboflavin per day.
Niacin, or vitamin B3, is a water-soluble vitamin that consists of nicotinic acid, nicotinamide and related forms of niacin, such as nicotinamide riboside.
Your body converts niacin into nicotinamide adenine dinucleotide (NAD), a coenzyme that plays a key role in more than 400 enzymatic reactions.
NAD is a particularly important coenzyme for producing energy from the nutrients found in food.
Common sources of niacin include beef liver, chicken breast, turkey breast, salmon, tuna, pork, ground beef, peanuts, marinara sauce, peanuts and fortified breakfast cereals.
The Office of Dietary Supplements recommends that men aged 19 or older consume 16mg of niacin or niacin equivalents per day.
Pantothenic acid, or vitamin B5, plays a major role in the synthesis of coenzyme A, an essential coenzyme that’s used in fatty acid synthesis and numerous anabolic and catabolic processes in the body.
Research suggests that pantothenic acid may be helpful for promoting cardiovascular health in people with high blood lipid levels.
Pantothenic acid can be found in almost all animal and plant-based foods. Rich sources of this B vitamin include beef liver, chicken breast, tuna, mushrooms, avocados, sunflower seeds, eggs and dairy products such as milk.
The Office of Dietary Supplements recommends that men aged 19 and above consume 5mg of pantothenic acid per day.
Vitamin B6 is a generic term that’s used to refer to the distinct compounds pyridoxine, pyridoxal, pyridoxamine and their 5’-phosphate esters.
These compounds are involved in a diverse range of processes within the body, including more than 100 enzyme reactions, many of which are related to protein metabolism.
Vitamin B6 also assists in cognitive development, immune system function and the production of hemoglobin, an essential protein found in red blood cells that transports oxygen throughout the body.
Common food sources of vitamin B6 include chickpeas, beef liver, tuna, chicken breast, salmon, potatoes, turkey, ground beef, bananas, marinara sauce and fortified breakfast cereals.
The Office of Dietary Supplements recommends that men aged between 19 and 50 consume 1.3mg of vitamin B6 per day. Men above the age of 50 should consume 1.7mg of vitamin B6 per day.
Biotin, or vitamin B7, is a key cofactor in numerous processes related to the metabolism of fatty acids.
It’s also an essential vitamin for healthy cell signaling -- a process that’s vital for a healthy immune system and processes such as tissue repair.
People who are deficient in biotin often have weak, brittle nails, skin rashes and temporary hair shedding. Because of this, biotin is often promoted as a supplement for healthy hair, skin and nails.
Biotin is produced naturally in your small intestine, but it’s also found in certain foods.
Common sources of biotin include beef liver, salmon, eggs, pork, ground beef, tuna, sunflower seeds and sweet potatoes.
The Office of Dietary Supplements recommends that men aged 19 and older should consume 30mcg of biotin per day.
Folate, or vitamin B9, is an essential vitamin that functions as a coenzyme or cosubstrate in the synthesis of DNA. It’s also used to produce red blood cells, which transport oxygen throughout your body.
In addition to these roles, folate promotes a healthy appetite and assists in bodily processes like tissue growth and cell function.
Natural sources of folate include beef liver, black-eyed peas, spinach, brussels sprouts, mustard greens, asparagus, fortified breakfast cereals, spaghetti and bread.
The Office of Dietary Supplements recommends that men aged 14 and up consume 400mcg of folate per day.
Vitamin B12 plays a key role in protein metabolism. It also helps to produce red blood cells and maintain your central nervous system.
Good sources of vitamin B12 include beef liver, fish, poultry, meat, eggs, milk and other dairy products. Some fortified cereals and nutritional yeasts also contain this vitamin.
The Office of Dietary Supplements recommends that adult men and women take in 2.4mcg of vitamin B12 per day.
While most people get enough vitamin B12 from their diet, some people lack a protein referred to as intrinsic factor, which is necessary for absorbing vitamin B12 from food.
B-complex vitamins play a number of important roles in, including helping enzymes to function and breaking down the essential nutrients that fuel your body and keep you healthy.
If you’re deficient in certain B vitamins, you may start to develop health issues. For example, a lack of vitamins B6 or B12 cause anemia -- a condition in which your blood lacks the red blood cells required to transport oxygen around your body.
Research suggests that vitamin B complex supplements may help to promote improved wound healing.
For example, a study published in the journal Advances in Skin & Wound Care found that some combinations of B vitamins improved wound closure in healing skin.
Additional research has found that use of vitamin B complex supplements may help to improve mood and performance.
However, it’s worth noting that this research was sponsored by Bayer -- a pharmaceutical brand that manufactures and markets its own line of vitamin B complex supplements.
Other B vitamins are recommended for their health benefits in certain situations. For example, pregnant women, older adults and people with health conditions that affect nutrient absorption are often advised to use vitamin B complex supplements.
Because all of the B vitamins are water soluble, your body does not store the excess.
In other words, regardless of how much vitamin B you consume, your body only ever uses the amount that it needs, with the rest excreted through your urine.
With the exception of biotin, which is created in your small intestine, the B vitamins need to be obtained from your diet.
If your diet is lacking in certain B vitamin-rich foods, or if you have a health issue that prevents you from absorbing nutrients properly, you may develop a B vitamin deficiency.
B vitamin deficiencies aren’t very common. However, when they do develop, they often involve multiple B vitamins that are lacking in your body.
Thiamine deficiency can affect your cardiovascular, immune and nervous systems, causing you to develop symptoms such as impaired reflexes, sensory deficits and heart dysfunction.
This type of deficiency can develop if you have a diet that’s very high in white rice or processed grains.
Certain health issues, such as chronic alcoholism, malnutrition or the effects of bariatric surgery, may increase your risk of developing a thiamine deficiency.
Riboflavin deficiency is very uncommon. It can develop due to endocrine issues, such as thyroid hormone deficiency, as well as certain diseases.
If you have a riboflavin deficiency, you may notice skin disorders, hair loss, sore throat, itchy or red eyes, as well as symptoms such as edema of the mouth and throat, swollen or cracked lips and angular stomatitis (lesions in the corners of your lips).
Like other B-complex vitamin deficiencies, niacin deficiency isn’t very common. It may develop in people who lack access to niacin and protein-rich foods, such as people living in poverty.
Niacin deficiency can cause a disease called pellagra, in which the skin develops a sunburned, rough appearance and a noticeable pigmented rash.
This can also affect the digestive system and cause symptoms such as diarrhea and vomiting.
Over time, pellagra can worsen and take a significant toll on a person’s health, making it vital to seek out treatment as symptoms become apparent.
Pantothenic acid deficiency is very uncommon. This is because pantothenic acid is found in the majority of foods and is rarely left out of a person’s diet.
When pantothenic acid does occur, it may cause symptoms such as numbness, fatigue, burning in the hands and feet, headache, sleep difficulties and gastrointestinal disturbances.
Like other B vitamin deficiencies, vitamin B6 deficiency is uncommon and typically develops at the same time as issues related to other B-complex vitamins.
This type of nutritional deficiency may occur in people with chronic kidney disease or conditions that affect nutrient absorption, such as Crohn’s disease, celiac disease or ulcerative colitis.
When vitamin B6 deficiency occurs, it can cause symptoms such as dermatitis with cheilosis (a form of scaling that affects the lips and corners of the mouth), a weakened immune system and psychological issues such as depression and confusion.
Biotin is produced inside your small intestine, meaning it’s rare to develop a deficiency. In fact, no cases of severe biotin deficiency have ever been reported in people that follow a balanced, normal diet.
When biotin deficiency does occur, it often causes gradual hair thinning that can progress to a severe form of hair loss that affects the entire body.
It can also cause symptoms such as a scaly, red rash near body openings, conjunctivitis, skin infection, brittle nails and neurological issues such as lethargy, hallucinations and depression.
Folate deficiency can develop in alcoholics, as well as people with health issues that affect their body’s ability to absorb nutrients.
When folate deficiency occurs, it’s often accompanied by other nutrient deficiencies. It can lead to a range of symptoms, including changes in skin, hair and fingernail color, shortness of breath, irritability, weakness, fatigue, difficulty concentrating and heart palpitations.
Vitamin B12 deficiency often occurs in vegetarians, as the only natural sources of vitamin B12 are animal foods such as meat and dairy.
It can also develop in older adults and people with conditions such as pernicious anemia or gastrointestinal disorders.
Common symptoms of vitamin B12 deficiency include fatigue, weight loss, tingling of the hands and feet, heart palpitations and glossitis (inflammation) of the tongue.
Vitamin B12 deficiency is also a common cause of a potentially serious condition called megaloblastic anemia.
Some B vitamins, such as biotin, play a significant role in your body’s process for growing and maintaining your hair.
If you’re deficient in these vitamins, you may notice that your hair doesn’t look as thick and full as it normally does. You may also notice that you’re shedding more hair than normal.
We’ve talked about these symptoms more in our guide to biotin and the role it plays in the hair growth process
While vitamin B complex supplements may help to stimulate hair growth, most research shows that they’re only effective if your hair loss is caused by a vitamin deficiency.
For example, unless you’re deficient in biotin, you probably won’t notice any positive change in your hair simply by taking a biotin or B-complex vitamin supplement daily.
As we mentioned above, deficiencies of specific B vitamins are not very common, especially in otherwise healthy people.
Because of this, there generally isn’t any reason to use a vitamin B complex supplement unless you’re specifically deficient in one or several B vitamins.
Instead, you’ll likely get better results by simply taking a daily multivitamin, which likely contains most of the essential B vitamins anyway.
Because B vitamins are water soluble, there’s little risk of consuming an excessive amount via supplementation.
When your body has more B vitamins than it can handle, it simply expels the rest through your urine.
With this said, some B vitamins have been linked to health issues when consumed in excessive amounts.
For example, extremely high intakes of vitamin B6 can cause nerve problems, including a loss of control over your bodily movements.
High doses of niacin may lead to flushing of the skin, hypotension, fatigue and gastrointestinal issues.
Over the long term, excessive use of some vitamin B complex supplements could contribute to liver issues.
These issues aren’t common and typically require you to take a very, very high dose of vitamin B complex supplements.
Although some B-complex vitamin deficiencies are associated with hair loss, taking B vitamins isn’t likely to improve your hair growth if you’re not deficient.
If you do have a B vitamin deficiency, you’ll almost always have noticeable symptoms such as those listed above.
Assuming you eat a relatively well-balanced diet and take a multivitamin, there’s little reason to take a vitamin B complex supplement.
Barring absorption problems, you’re likely getting enough of your B vitamins from your diet and regular daily vitamins.
Anything you use on top of this would simply be money down the toilet -- in this case, literally.