B complex vitamins and hair loss
B complex vitamins and hair loss


B vitamins play a key role in hair growth because they are necessary to produce red blood cells which carry oxygen to the scalp, they help turn food into energy and support the nervous system.  B vitamins are essential for normal cell growth, development and function.  The eight vitamins that make up the B-Complex are necessary for nearly every metabolic process in the body.  Due to the importance of B vitamins in normal metabolism, they offer a multitude of benefits to hair health.

There is only a small storage capacity for most B vitamins, except for vitamin B2 and vitamin B9 (folate) which is stored in the liver.  The limited storage capacity means that B vitamins must be consumed regularly to avoid deficiency.  Cooking, processing of food and alcohol consumption can reduce the availability of B vitamins.

Because B vitamins are water soluble, they can be taken as a supplement in high doses, any extra will simply be excreted.  There are nine B vitamins in total, known as the B-complex, that are extremely important to hair health.


B vitamins are a complex of water-soluble vitamins that your cells need for normal metabolism. They directly impact your levels of energy, cellular metabolism, and important bodily functions.

Each B vitamin is either a precursor for a cofactor, or a cofactor itself, needed for vital metabolic functions.  A cofactor is a non-protein chemical compound that works as a “helper molecule” to assist biological reactions.  These vitamins share similar names, but they are chemically different. They usually co-exist in the same dietary sources.

There are nine vitamins that make up the B-complex:

  • Vitamin B1 / Thiamine
  • Vitamin B2 / Riboflavin
  • Vitamin B3 / Niacin
  • Vitamin B4 / Choline
  • Vitamin B5 / Pantothenic acid
  • Vitamin B6 / Pyridoxine
  • Vitamin B7 / Biotin
  • Vitamin B9 / Folate
  • Vitamin B12 / Cobalamin

Generally we can achieve our vitamin B requirements by eating nutrient dense food, though it is possible to develop a B vitamin deficiency if you have any type of inflammatory bowel condition (IBS or IBD), bile reabsorption issues, malabsorption, imbalanced gut bacteria or a poor diet.

Generally we can achieve our vitamin B requirements by eating nutrient dense food, though it is possible to develop a B vitamin deficiency if you have any type of inflammatory bowel condition (IBS or IBD), bile reabsorption issues, malabsorption, imbalanced gut bacteria or a poor diet.


Why is it important for hair health? Thiamine is a sulphur containing compound and is important for the activation of phase I detoxification in the liver.

Thiamine is crucial for the breakdown of carbohydrates into glucose [1], glucose is the primary fuel source for the fast-dividing keratin cells within the hair follicle.  Thiamine is also needed for the conversion of glucose to ATP within the cell, ATP is the energy currency used by all cells to function, keratin cells are especially sensitive to low ATP output.

Vitamin B1 / thiamine deficiency symptoms: Weight loss or weight gain, low or increased appetite, loss of muscle mass, heart palpitations and poor reflexes.

Food sources of vitamin B1 / thiamine: Beef, tofu, mushrooms, pork, fish, eggs, milk, yogurt, almonds, avocados, buckwheat, quinoa, brown rice.

Vitamin B1 / thiamine stability: The destruction of vitamin B1 amounts to up to 22% in cooked vegetables with an additional 15% dissolved on cooking water.  when cooking water is discarded this amounts to 20-35%.


Why is it important for hair health? Deficiency of riboflavin leads to the inhibition of the liver detoxification pathways that eliminate bacterial toxins.  Vitamin B2 supports fatty acid metabolism that improves energy production in nerve cells in turn preventing the secretion of Substance P, a neuropeptide associated with alopecia areata and telogen effluvium due to induction of catagen phase in the hair growth cycle.

Riboflavin deficiency has no clear clinical features and often presents alongside other nutritional deficiencies [2].  Low levels of riboflavin affect the structure of villi in the intestine [3] and is shown to contribute to poor iron absorption leading to iron deficiency.  Metabolic changes can occur leading to an increased energy need to maintain normal body weight [4-5], failure to meet this need will result in the increase of fat cells as the body attempts to counteract the nutritional deficit.  Fat cells are efficient cortisol factories and increased cortisol in circulation will reduce the production of insulin-like growth factor, an important growth factor for hair growth.

Vitamin B2 deficiency / riboflavin symptoms: Slow detoxification of alcohol and caffeine, low thyroid function, dandruff, poor digestion, cracks at the corner of your mouth.

Food sources of vitamin B2 / riboflavin: Beef, tofu, mushrooms, pork, fish, eggs, milk, yogurt, almonds, avocados, buckwheat, quinoa, brown rice.

Vitamin B2 / riboflavin stability: Sensitive to light and high temperature.  Foods containing vitamin B2 / riboflavin should be kept out of sunlight and not placed in clear containers. Vitamin B2 / riboflavin will be destroyed when cooked at a temperature of over 121˚C.


Why is it important for hair health?  Niacin improves blood circulation and can support the delivery of oxygen and nutrients to the hair follicle [6].  Niacin also facilitates the removal of waste products from the keratin cells in the hair follicle.

Niacin has been used to lower cholesterol as it is active in fat deposition and metabolism [7]. High levels of cholesterol and cholesterol metabolites around the hair follicle are linked to a reduction in the hair growth cycle.

Niacin is needed to produce hydrochloric acid, necessary for the stomach acid that sterilises and begins the breakdown of food in the stomach.  Another role niacin plays in the digestive system is the production of bile, needed for the uptake of fat-soluble vitamins like vitamin D.

Vitamin B3 / Niacin deficiency symptoms: Low stomach acid, acid reflux, high LDL cholesterol even with a good diet, low mood.

Food sources of Vitamin B3 / Niacin: Beef, liver, pork, bananas, nuts and seeds.

Vitamin B3 / Niacin stability: In normal food preparation niacin is only moderately affected.  Not affected by light or heat but can be diminished by up to 40% by boiling or blanching. Large losses during the milling and processing of grains and cereal.


Why is it important for hair health? Essential for fatty acid metabolism.  Surface cells of the hair shaft are abundant in fatty acids, and about 40% of such fatty acids are composed of 18-methyl-eicosanoic acid (18-MEA), this is the major cell membrane binding complex that cements the hair cuticle.

Vitamin B5 / pantothenic acid deficiency symptoms: Seborrheic dermatitis, premature greying, impaired immunity, rough hair fibre.

Food sources of vitamin B5 / pantothenic acid: Beef, liver, pork, broccoli, sunflower seed and chickpeas.

Vitamin B5 / pantothenic acid stability: Moderate loss when cooking vegetables, up to 30% loss in cooked meats.


Why is it important for hair health? Vitamin B6 plays a role in the protein metabolism of keratin and melanin.  Vitamin B6 can also bind to testosterone, thus limiting the actions of the testosterone metabolites associated with androgenic alopecia.  The vitamin can also positively regulate the function of estrogen and testosterone via a derivative known as pyridoxal-5-phosphate.

Vitamin B6 / pyridoxine deficiency symptoms: Seborrheic dermatitis, premature greying, impaired immunity.

Food sources of vitamin B6 / pyridoxine: Pork, peanuts, wheatgerm, chicken, oats, soya beans.

Vitamin B6 / pyridoxine stability: Cooking loss is higher when food is boiled, followed by foods that are deep fried and then sautéed.


Why is it important for hair health? Biotin is a sulphur containing molecule essential for keratin production. Keratin is a protein that your body uses as a building block for hair, skin, and nails.

In a 2017 study, intestinal dysbiosis and biotin deprivation was shown to induce alopecia through overgrowth of Lactobacillus murinus [7].

Vitamin B7 / thiamine deficiency symptoms: Thinning hair, brittle nails, dry or scaly skin.

Food sources of vitamin B7 / thiamine: Pork, peanuts, wheatgerm, chicken, oats, soya beans.

Vitamin B7 / thiamine stability: When tested, destruction of vitamin B7 was as much as 35% in vegetables boiled in water.


Why is it important for hair health? Folate is essential for appropriate DNA transcription in the hair follicle. Within a hair follicle, one of the segments of DNA utilised produces keratin, lots and lots of keratin.  The keratin produced by the hair follicle makes long fibres and continues to grow within the dermis (just under scalp level). This keratin emerges from your scalp as hair.

Symptoms of vitamin B9 / folate deficiency include: Symptoms similar to anaemia, lack of energy, fatigue, shortness of breath.

Food sources of vitamin B9 / folate: Broccoli, liver, chickpeas and kidney beans, leafy green vegetables, citrus fruits, beans, fortified cereals.

Vitamin B9 / folate stability: An extensive amount of folate (50-90%) is lost during cooking.


Why is it important for hair health? This B vitamin is an essential cofactor in the synthesis of amino acids and fatty acids that are necessary for hair growth.  Vitamin B12 deficiency results in low energy levels due to impaired red blood cell production.  The inhibited red blood cell production impacts the oxygen supply to the hair follicles and results in slower hair growth and thinner hair.

Symptoms of vitamin B12 / cobalamin deficiency include Fatigue, disorders of the small bowel, stomach and intestines.

Food sources of vitamin B12 / cobalamin: Broccoli, liver, chickpeas and kidney beans, leafy green vegetables, citrus fruits, beans, fortified cereals.

Vitamin B12 / cobalamin stability:  Cooking only reduces levels of vitamin B12 by around 20%.  Boiling foods with vitamin B12 also reduce nutritional value.


B vitamins contribute to the maturation of keratin cells within the har follicle and several other metabolic processes that support hair growth.  Whilst there is no solid evidence that B vitamins contribute directly to hair growth due to a lack of investigation in this specific area, their pivotal role in blood circulation, red cell production and liver function make them likely to be essential for the maintenance of healthy hair.


  1. Vitamin deficiency, in Conns’ Current Therapy. Rakel, R.E., ed., W.B. Saunders,Philadelphia, p. 551, 1994.
  2. Cytokinetic and structural responses of the rat small intestine to riboflavin depletion. Br. J. Nutr., 75, 315, 1996.
  3. Pharmacokinetics of orally and intravenously administered riboflavin in healthy humans. Am. J. Clin. Nutr., 63, 54, 1996.
  4. Uptake of riboflavin across the brush border membrane of rat intestine: regulation by dietary vitamin levels. Gastroenterology 105, 1294, 1993.
  5. Thiamine deficiency in diabetes mellitus and the impact of thiamine replacement on glucose metabolism and vascular disease. International journal of clinical practice, 65(6), pp.684-690.
  6. Effect of niacin on the choroidal circulation of patients with age related macular degeneration. British journal of ophthalmology, 88(12), pp.1568-1572.
  7. Intestinal dysbiosis and biotin deprivation induce alopecia through overgrowth of Lactobacillus murinus in mice. Cell reports, 20(7), pp.1513-1524.