Thinning hair, weak nails? How biotin – vitamin B7 – could help strengthen both, and fix dry skin, and its other essential functions
- Vitamin B7, also known as biotin, plays a vital role in assisting enzymes to break down fats, carbohydrates and proteins in food, converting them to energy
- It is also key in the growth of keratin – a protein naturally produced by the body that keeps our hair, skin and nails healthy and strong
Last year, Anna Flores noticed that she was losing more hair than usual, particularly while shampooing and brushing her locks.
She read that biotin, or vitamin B7, was good for strengthening hair follicles, so she started taking a biotin supplement every day. Not long after, the hair shedding decreased – and she noticed that her skin looked healthier, too.
“Although more studies need to be done to show that biotin can help improve the health of our hair, skin and nails, I take the supplements regularly anyway because I’ve had positive results,” says Flores, who is in her “mid-to-late 40s” and is the founder of The Chaless Wellness and Beauty spa in Central in Hong Kong.
Cyrus Luk, a Hong Kong dietitian and an executive committee member of the Hong Kong Dietitians Association, says vitamin B7 is considered essential because it provides a range of functions.
It also regulates immune function, antibody production and lymphocyte differentiation – in which activated B cells or T cells become specialised immune cells – and regulates signals sent by our cells and the activity of our genes.
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Luk adds that vitamin B7 has been shown to play an important role in the growth of keratin – a protein naturally produced by the body that keeps our hair, skin and nails healthy and strong – and the integrity of our hair follicles.
The top animal-derived food sources of vitamin B7 are chicken liver, pork liver, egg yolks, salmon and pork chops. The top plant-based sources are edamame (young soybeans), sunflower seeds, button mushrooms, sweet potatoes, almonds, and broccoli.
There are a few things to be aware of when it comes to vitamin B7, says Luk.
It is a water-soluble vitamin, “meaning that it will get lost in the cooking water while boiling, so it’s probably not a good idea to overboil foods that are rich in this vitamin”.
“Second, avidin – a protein found in raw egg white – binds vitamin B7 in the gut and prevents its absorption. I therefore wouldn’t recommend consuming biotin-rich foods with raw egg white.”
He adds that biotin deficiency has been seen in people who have eaten raw egg white over long periods.
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So, how much vitamin B7 should we consume? Luk says that adult men and pregnant women require 30 micrograms (mcg) per day, while adult women require 25mcg per day and lactating women 35mcg per day.
“To put these amounts into perspective, 100g of chicken liver has 184mcg of biotin, 100g of edamame has 19mcg, one whole egg has 10mcg, a quarter-cup of sunflower seeds contains 2.6mcg, half a cup of sweet potato has 2.4mcg, and half a cup of broccoli contains 0.4mcg.”
There is no evidence that biotin is toxic in humans in large amounts, Luk adds. However, supplementing with biotin beyond the recommended daily intake can cause clinically significant falsely high or falsely low laboratory test results, leading to inappropriate patient management or misdiagnosis of a medical condition.
It is impossible to consume too much vitamin B7 from food alone, Luk says.
While biotin may help us maintain healthy hair, skin and nails, Flores points out that it is not a magic bullet by itself.
“But, from my experience, taking a biotin supplement daily can certainly help enhance the effects of these good habits.”
