Vitamin B8 or biotin or vitamin H is a water-soluble vitamin, like all the other B vitamins.
It is produced by the body in the intestinal flora, but is easily excreted in the urine.
Good dietary intake and sometimes supplementation is required.
It plays a vital role in the proper functioning of our bodies and, like all vitamins, is essential.
The benefits
Key role in nutrient metabolism
This vitamin is a coenzyme that plays a key role in nutrient metabolism.
In lipid metabolism, it is involved in the biosynthesis of certain amino acids.
It also facilitates the assimilation and utilisation of fats in the body.
In the metabolism of carbohydrates, it ensures their conversion into glucose.
It also helps to stabilise blood sugar levels.
At the protein level, it contributes to the synthesis of amino acids.
It therefore plays an essential role in the production of energy and thus fuel for the body.
It is also involved in the synthesis of other vitamins such as B9 and B12.
Improves skin condition
Vitamin B8 deficiency can cause skin disorders (e.g. dermatitis or acne).
Protects the skin from cell oxidation.
It also promotes cell renewal and has important moisturising properties.
Biotin therefore reduces wrinkles and the effects of premature ageing.
Strengthens fingernails
Biotin also improves the health and quality of your nails.
A good intake helps to keep nails stronger and less brittle.
Hair loss
Vitamin B8 is often used to treat hair loss, with the aim of slowing it down.
It can also be found in certain shampoos, lotions, conditioners or medical treatments for these hair problems.
Vitamin B8 requirements
As with any macro- or micronutrient, requirements change over time.
Here are the vitamin B8 requirements for different populations:
Population - µg/day
- Infant = 6
- Child 1 to 3 years = 12
- Child 4 to 9 years = 20 to 25
- Child 10 to 15 years = 35 to 45
- 16 years and older = 50
- Pregnant woman = 50
- Nursing woman = 55
- Senior woman = 60
- Senior man = 50
The average daily requirement of vitamin B8 for an adult is therefore 50 µg.
In general, this is easily met by the body's own synthesis and a good diet.
Deficiencies can occur with certain consequences.
However, an excess of this vitamin does not occur because the excess is excreted in the urine.
If biotin is used for these benefits in the hair, skin or nails, it is interesting to supplement with 15 mg/day.
A varied diet can usually cover this requirement quite easily.
Where can we find it in our diet?
Biotin is found in varying amounts in many everyday foods.
Here they are:
Food - µg/100g
- Brewer's yeast = 179mcg/100g
- Royal jelly = 107µg/100g
- Oilseeds (average) = 49mcg/100g
- Offal = 35mcg/100g
- Wholemeal bread = 32mcg/100g
- Pulses = 18mcg/100g
- Boiled eggs = 16mcg/100g
- Lettuce = 10mcg/100g
- Brie cheese = 8mcg/100g
- Red fruits = 4µg/100g
Interactions
Certain substances can prevent vitamin B8 from being properly absorbed by the body, leading to deficiency.
This is the case with certain drugs, including antibiotics and epilepsy treatments.
By altering the composition of the gut microbiota, they reduce the assimilation of this vitamin.
Eating raw eggs with avidin in the albumen retains vitamin B8 and prevents its proper assimilation.
This is also the case with alcohol.
Chemical property
Biotin exists in 8 different forms, but only D-biotin occurs naturally and has vitamin activity.
It consists of a 2-imidazolidinone core fused to a thiolane core to which a pentanoic acid group is attached.