Vitamin B7 – Biotin

Why do you need it?

Biotin helps us convert food into energy and is essential for a healthy liver, eyes, hair, skin, nails and nervous system. The bacteria in your bowel are able to make some biotin but it’s not clear how much we need from the diet so the below is mostly a healthy recommendation.


Symptoms of deficiency include hair loss, brittle nails, rashes or other skin problems, poor sugar metabolism (the way your body handles sugar), depression and exhaustion. Symptoms of biotin deficiency in infants can include weak muscles, a lack of energy and delayed development.

How much do you need?

The World Health Organisation (WHO) recommends 30 micrograms (μg) of biotin a day for adults aged 19 and over. The recommended intakes for infants, children, adolescents and pregnant and lactating women are given below.

Recommended nutrient intakes for biotin. Click to read more…
Age groupRecommended nutrient intake
Infants and children
0-6 months6
7-12 months6
1-3 years8
4-6 years12
7-9 years20
Females, 19+30
Males, 19+30
Pregnant women30
Lactating women35
Source: WHO, FAO. 2004. Vitamin and mineral requirements in human nutrition. 2nd ed. Geneva: WHO.

Where to find biotin

The best plant sources of biotin include nuts, seeds, avocados, sweet potatoes, mushrooms, whole grains, leafy greens and pulses.

  • Nuts and seeds: Eating a variety of nuts and seeds is good but peanuts, sunflower seeds and almonds are best for biotin. A small handful (28 grams) of roasted peanuts contains 5.0 micrograms of biotin, quarter of a cup (35 grams) of sunflower seeds contains 2.6 micrograms and a small handful (28 grams) of roasted almonds contains 1.5 micrograms. 
  • Avocados: A great source of biotin, a medium avocado (200 grams) may contain 7.2 micrograms of biotin. Avocados can be eaten raw, mashed on toast, made into guacamole, or sliced for salads and burritos.
  • Sweet potatoes: Half a cup (100 grams) of cooked sweet potato contains around 2.4 micrograms of biotin. They can be enjoyed baked, roasted or mashed.
  • Mushrooms: 20 button mushrooms (120 grams) may contain 2.6 micrograms of biotin. Mushrooms are a versatile ingredient that can be added to many savoury dishes.
  • Whole grains: Foods like brown rice, quinoa and oats provide a good source of biotin if eaten regularly. Opting for wholegrain products instead of refined grains can increase your biotin intake.
  • Leafy Greens: Kale, spinach and Swiss chard are examples of leafy greens that contain moderate amounts of biotin. A cup (180 grams) of cooked spinach contains 1.0  microgram of biotin.
  • Pulses: Peas, beans and lentils are a moderate source of biotin. One cup (198 grams) of cooked lentils contains 1.8 milligrams of biotin.