How Can Too Much Biotin - Vitamin B7 - Cause Hair Loss?'

Name: J

Question: Why would too much b7 cause hair loss? Will hair regrow after stop dosage? Thanks

Answer: Hi, J. Regular intake of excessive quantities of certain nutrients can cause hair loss in some cases due to a temporary condition known as Telogen Effluvium. However, the effects of too much vitamin B7 - also known as biotin toxicity - remain unconfirmed.

In order to answer your query fully, I will explain how B7, also known as biotin, Vitamin H or Vitamin B8, can be beneficial to the hair and when its levels can cause or contribute to hair thinning.

Clear, established health benefits associated with dietary intake of biotin have been confirmed by the European Food Safety Authority (EFSA). This relates to vitamin B7 supporting the normal maintenance a number of functions including macronutrient metabolism, the nervous system, psychological functions and hair growth. The European Commission advises that biotin contributes to normal energy-yielding metabolism and to the maintenance of normal hair and skin.

Biotin is one of the key nutrients necessary for healthy hair growth, however very small amounts are actually needed. It is a water soluble vitamin but, unlike other vitamins of this kind, natural food sources can only provide low levels of biotin. Food sources include yeast, liver, egg yolks, soya, nuts and cereals.

According to the UK's Department of Health "bacteria that live naturally in your bowel are able to make biotin, so it's not clear if you need any additional biotin from the diet". As a result of this, biotin deficiency is rare though some groups of people who may have an increased risk of developing biotin deficiency. These include dialysis patients, people with diabetes, and patients with an impaired uptake of vitamins from food. A marginal biotin deficiency can also very occasionally be found in pregnant women.

Despite a recommended daily intake of 30-40mcg a day for adults, as with many nutrients, how much you need depends on the individual. Whilst the UK Department of Health advises that, for adults, "taking 0.9mg or less a day of biotin in supplements is unlikely to cause any harm", the US Department of Health and Human Services website states, “The FNB was unable to establish ULs for biotin because there is no evidence in humans that biotin is toxic at high intakes. Several studies have found no adverse effects of 1050 mg/day biotin, and up to 200 mg/day oral biotin or 20 mg/day intravenously in patients with biotinidase deficiency do not produce symptoms of toxicity".

Symptoms of biotin deficiency are known to include hair loss and loss of hair colour, dry scaly skin, cracked lips, a swollen and painful tongue, dry eyes, a loss of appetite, fatigue, insomnia and depression.

Symptoms of excessive biotin intake are believed to include, cystic acne, increased urination, diarrhoea, mild nausea and acute respiratory problems. It is important to note, however, that these reports are largely anecdotal and the amounts of vitamin B7 involved are also mostly unknown.

Though biotin is not considered toxic, the Linus Pauling Institute reports one instance of the life-threatening disease eosinophilic pleuropericardial effusion in an elderly woman who was taking 10,000 mcg per day of biotin and 300 mg per day of pantothenic acid over the course of two months. The Oregon State University-based institute also advises that dosages of up to 5,000 mcg per day taken by healthy individuals for two years were not associated with adverse affects.

The US Department of Health and Human Services advises: "Very high intakes of biotin can interfere with assays that use biotin-streptavidin technology and are commonly used to measure thyroid and other hormone levels. As a result, a few recent case reports have described findings falsely indicating Graves disease and severe hyperthyroidism in patients taking 10300 mg biotin per day, including six children receiving high doses of biotin (215 mg/kg body weight per day) to treat inherited metabolic diseases. Furthermore, high biotin intakes could produce false-negative or false-positive results from assays of vitamin D metabolites as well as cortisol, testosterone, estradiol, insulin, and other hormones”.

Diet-related hair loss, such as that caused by an excess or deficiency in certain nutrients, is known as Telogen Effluvium. This a temporary hair loss condition which causes hair thinning from all over the scalp. It can appear to be sudden and intense - with up to 50 per cent of the hairs being affected - though it actually takes around three months from being triggered to becoming noticeable. As there are a number of alleged side-effects mentioned in relation to extreme over consumption of biotin, it may well be that any hair loss is a result of the body being 'out of sorts' or adjusting to this new regime rather than as a direct result of the biotin itself.

The reason this type of hair fall occurs relates to a 'blip' in the hair growth cycle. When the body is placed under strain, whether through emotional of physical stress, illness or a dietary imbalance, it tries to protect itself. In doing so, nutrients may be diverted away from non-critical functions such as hair growth in order to concentrate on keeping the heart and lungs functioning properly. This can result in a number of hair follicles being 'jolted' into the hair growth cycle's resting period - known as the Telogen phase - prematurely. In doing so, in line with the cycle's natural timing, it can take around three months for these hairs to start shedding, and around six months to resume normal hair growth.

Telogen Effluvium treatment to help accelerate this process is available from specialist hair loss clinics who will start by assessing your scalp to ensure a correct diagnosis. This is particularly important when dealing with thinning hair as Telogen Effluvium can present simultaneously alongside, or even trigger genetic hair loss in men and women with an existing predisposition. They may not have noticed signs of Male Pattern Baldness or, for women, Female Pattern Hair Loss prior, but a specialist will be able to spot precisely what is going on and tailor a bespoke hair loss treatment course based upon their findings.

If the cause of your hairloss was solely down to a nutritional issue then this should resolve itself within the timelines stated above once you cut back. As vitamin B7 is water soluble it can exit your system fairly quickly through urination. If androgenetic alopecia has been triggered, or if it was already present and this has simply made it worse, then the rate of shedding may decrease once your nutritional profile normalises, however, as this is a permanent hair loss condition, the shedding will continue unless preventative treatment is sought.

As before, biotin overdoses are incredibly rare but, if you are concerned about your nutrient levels and any potential excesses or deficiencies, you should consult your doctor who can arrange tests, if necessary.