MikronährstoffCoach®: Mikronährstoffe / mikronaehrstoffcoach.com

Sources and physiological effects

Dietary sources
Biotin is widespread in animal and vegetable foods, albeit in mostly in small quantities. Biotin-rich animal foods include egg yolk, yeast and offal. Good plant sources are soybeans, nuts, rice bran and oat flakes. Biotin of plant origin occurs in free form, while in animal foods it is usually bound to lysyl residues. Small amounts of biotin are also produced by the intestinal flora. The glycoprotein avidin, contained in egg white, reduces the bioavailability of biotin by forming a complex with biotin that cannot be broken down enzymatically in the gastrointestinal tract. By heating the egg to 100° C over a longer time, avidin is denatured and loses its biotin-binding property. In practice, however, this complex binding does not play a role in normal nutrition. When processing food, the biotin content of a meal is only slightly reduced. Only at high temperatures and under the influence of UV light is part of the biotin content destroyed.
Physiological effects
Skin and hair	Co-factor in the build-up and breakdown of protein structures Stimulation of epidermal cell differentiation
Metabolism	Biotin plays an important role in protein, fat and carbohydrate metabolism as a co-factor for various carboxylases
Carbohydrate metabolism	A key enzyme of gluconeogenesis involved in the regulation of blood sugar levels
Blood	Co-Factor in the formation of erythrocytes, lymphocytes and antibodies

EFSA Health Claims

Health claims		EFSA opinion
Biotin	Contributes to a normal energy metabolism Contributes to a normal function of the nervous system Contributes to a normal metabolism of macronutrients Contributes to the maintenance of hair Contributes to the maintenance of mucous membranes Contributes to the maintenance of skin

Recommended intake

D-A-CH Reference values for the intake of biotin (Reference values EFSA and NHI )
	Age	Biotin (µg/d)
Infants (months)
	0-4	5
	4-12	5 - 10
Children (years)
	1-4	10 - 15
	4-7	10 - 15
	7-10	15 - 20
	10-13	20 - 30
	13-15	25 - 35
Youth/Adults (years)		Women	Men
	15-19	30 - 60	30 - 60
	19-25	30 - 60	30 - 60
	25-51	30 - 60	30 - 60
	51-65	30 - 60	30 - 60
	> 65	30 - 60	30 - 60
Pregnancy	30 - 60
Breastfeeding	30 - 60
Higher needs groups	Older people, alcohol abuse, malabsorption from intestinal dysbioses, and short bowel syndrome

Recommended intake according to the food labelling regulations

(=100 % TB marking on label)

50 µg

Nutrient safety

UL

Long-term daily intake at which no negative health effects are to be expected

N/A

NOAEL

Maximum intake that, in studies, did not cause adverse effects

2500 µg/d (Gröber)

9000 µg/d (UK expert group)

Safety

The European Group on Vitamins and Minerals (EVM) has been looking at the safety of biotin

Detailed information

Biotin - important for the development of skin and nails

Biotin is a water-soluble vitamin needed for normal development and differentiation of the skin. It causes storage of sulfur-containing amino acids in the hair root cells and in the nail-forming cells and thus promotes the proportion of stabilizing keratin matrix proteins. Knowledge of human biotin requirements is incomplete, the current intake is generally regarded as sufficient (1). Nevertheless, supplementation at higher doses shows effective therapeutic results. Clinical studies have shown that a daily dose of 2.5 mg biotin over 6 months significantly improved the quality of brittle nails. Nail thickness, surface structure and strength were improved in 91% of patients (2).

Biotin for dry skin and eczema

This pharmacological effect has since been substantiated in further controlled studies (3). Studies on the mechanism of action have shown that biotin directly stimulates the differentiation of epidermal cells and thus increases nail quality (4). Increased biotin intake can also be used therapeutically for scaly, dry skin and eczema. Together with the trace elements iron, zinc and copper, a broad spectrum of treatments is covered, ranging from disorders in collagen and elastin metabolism, skin lesions and angular cheilitis to cracked skin susceptible to infection and seborrheic dermatitis. Inadequate intake of biotin, iron, zinc or copper can also result in disorders of hair and nail growth, hair loss and the detachment of the nail from the nail bed (1).

Reference values

Substrate	Parameter	Reference value	Description
Biotin	Serum/Plasma	200 - 1000 µg/l Limited value 200 - 300 µg/l	Fasting (12 h nil by mouth) Radioimmunoassay or enzyme immunoassay after binding to streptavidin.
Interpretation
Low values		Indication of biotin deficiency. Limited values may be associated with reduced activity of biotin-dependent enzymes.
High values		Overdose of biotin.

Deficiency symptoms

Impact on	Symptoms
General health	Loss of appetite, drowsiness, weakness
Skin	Dry, flaky skin Seborrhoeic dermatitis
Eyes	Keratoconjunctivitis
Hair	Hair loss, dry and brittle hair
Nails	Fragile or cracked nails
Musculature	Muscle pain, paresthesia, neuropathy
Blood	Anemia

Indications

Effect	Indication	Dosage
Physiological effect at a low intake	For general prevention	0,1 - 0,3 mg/d
	For therapeutic use with fragile, splintering nails and Beau's lines	1 - 2,5 mg/d
	To cover increased needs in the case of hair growth disorders and hair loss hair loss	1 - 2,5 mg/d
	Complementary therapeutic for dry and scaly skin	1 - 2,5 mg/d



Pharmocologic effect at a high intake	For therapeutic use in seborrhoeic dermatitis	10 - 20 mg/d
	For the therapeutic treatment of neurological deficits due to biotin deficiency	10 - 15 mg/d

Administration

General mode of administration
When	Biotin should be taken before or with meals.
Side effects
No known side effects to date.
Contraindications
No known contrainidcations to date

Interactions

Drug interactions
Antiepileptics (e.g. phenytoin)	Treatment with antiepileptics leads to a decrease in blood biotin levels (absorption, excretion).
Nutrient interactions
Trace elements	Chromium and biotin show synergistic effects on blood sugar levels.
Fatty acids	Alpha-lipoic acid can inhibit biotin-dependent enzymes.
Vitamins	In high doses pantothenic acid seems to impair the uptake of biotin.

Description and related substances

Description

Water-soluble vitamin

Related substances

Only permitted in D-biotin form.

References

1) Hahn, A. et al. 2005. Ernährung. Physiologische Grundlagen, Prävention und Therapie.

2) Colombo, V. E. et al. 1990. Treatment of brittle fingernails and onychoschizia with biotin: Scanning electron microscopy. Journal of the American Academy of Dermatology 23, Nr. 6: 1127–1132. doi:10.1016/0190-9622(90)70345-i.

3) Hochman, L. G. et al. 1993. Brittle nails: response to daily biotin supplementation. Cutis. 51(4):303-5.

4) Fritsche, A. et al. 1991. Pharmacologic effects of biotin on epidermal cells. Schweiz Arch Tierheilkd. 133(6):277-83.

References Interactions:

Stargrove, M. B. et al. Herb, Nutrient and Drug Interactions: Clinical Implications and Therapeutic Strategies, 1. Auflage. St. Louis, Missouri: Elsevier Health Sciences, 2008.

Gröber, U. Mikronährstoffe: Metabolic Tuning –Prävention –Therapie, 3. Auflage. Stuttgart: WVG Wissenschaftliche Verlagsgesellschaft Stuttgart, 2011.

Gröber, U. Arzneimittel und Mikronährstoffe: Medikationsorientierte Supplementierung, 3. aktualisierte und erweiterte Auflage. Stuttgart: WVG Wissenschaftliche Verlagsgesellschaft Stuttgart, 2014.