Biotin, also known as vitamin B7, is best known for its role in supporting normal hair and skin – but it does plenty of quieter work too, helping your body turn food into energy. Here's what biotin does, where to find it, and when a supplement might help.
What does biotin do?
Biotin's name comes from the Greek word biotos, meaning "sustenance" or "life-giving" – a fitting name for a nutrient your body relies on daily. One of its most important jobs is helping break down the carbohydrates, fats and proteins in your food and turn them into usable energy, which is why biotin contributes to normal energy-yielding metabolism and to normal macronutrient metabolism.
It's also the B vitamin most associated with hair and skin. Biotin contributes to the maintenance of normal hair and the maintenance of normal skin – both tissues that renew themselves constantly – which is a big part of why it's become such a familiar name in everyday wellness. Beyond that, biotin contributes to the normal function of the nervous system and to normal psychological function.
Because biotin is water-soluble, your body doesn't store it, which means you need a fresh supply through your diet (or a supplement) each day.
What foods are high in vitamin B7?
You can get the biotin you need through a balanced diet. Good sources include cooked eggs, beef liver and kidney, salmon and sardines, and dairy products like milk and cheese. Plant-based sources include sweet potatoes, roasted almonds, spinach, broccoli and bananas.
One nice bit of detail: eggs should be cooked, because a protein in raw egg white binds to biotin and blocks its absorption – cooking deactivates that protein, so your body can take the biotin up as normal. It's a genuine quirk of this particular nutrient.
Interestingly, the bacteria in your large intestine can also produce small amounts of biotin, some of which may be absorbed. That said, the contribution is modest – most of your biotin comes from food, absorbed higher up in the small intestine. Between the two, and because biotin is so widely available in the diet, deficiency is rare.
Should I take a biotin supplement?
Most people get all the biotin they need from a balanced diet. Because it's the B vitamin most linked to hair and skin, biotin supplements have become popular with people looking to support the maintenance of normal hair and skin as part of their routine – and for those who'd like the reassurance of a steady, guaranteed intake, a supplement is a simple option.
You can take biotin as an individual supplement or as part of a B-complex formula that contains all the B vitamins. The NHS advises not taking more than 0.9mg a day, so as with any supplement, it's sensible to follow the recommended dose rather than assume more is better.
Should you take biotin during pregnancy?
Biotin requirements can be a little higher during pregnancy. However, as with all supplements in pregnancy, it's best not to start taking biotin without first checking with your doctor or midwife – they can advise on whether it's needed and at what dose. High doses in particular are best avoided unless a healthcare professional recommends otherwise.
Explore further
This piece from our Discover blog picks up where this article leaves off:
- Are beauty supplements worth it for skin and hair? – a level-headed look at what to expect from supplements in a beauty routine.
Explore our range of biotin supplements, or browse our vitamin B complex formulas containing all eight essential B vitamins.