Vitamin B8: Benefits, Dosage, Contraindications
Other name(s)
Biotin, Vitamin B7, Vitamin H
Family or group:
Vitamins
Indications
Rating methodology
EFSA approval.
Vitamin B8 Deficiency ✪✪✪✪✪
Biotin deficiency occurs in overall hypovitaminosis, where all group B vitamins are lacking, often others as well, such as after antibiotic therapy or during improper diets (for example, only consuming egg whites). Clinical signs are non-specific, such as scaly dermatitis with atrophy of sebaceous glands and hair follicles, anorexia, nausea, or even neurological signs. In cases of biotin deficiency, a dose of up to 10 mg per day has been used.
Posologie
Oral
10 mg
Adults
Type 2 Diabetes ✪✪✪✪✪
Clinical research shows that taking 2 mg of biotin combined with 600 mcg of chromium (as chromium picolinate) may lower blood glucose and hemoglobin A1C (glycated hemoglobin) levels in type 2 diabetes patients not well controlled by oral antidiabetic treatment. However, taking biotin alone does not seem to affect glucose levels in type 2 diabetes patients.
Posologie
Oral
2 mg
Adults
Synergies
Chromium picolinate and biotin combination improves glucose metabolism in treated, uncontrolled overweight to obese patients with type 2 diabetes.
The effect of chromium picolinate and biotin supplementation on glycemic control in poorly controlled patients with type 2 diabetes mellitus: a placebo-controlled, double-blinded, randomized trial.
Multiple Sclerosis ✪✪✪✪✪
Clinical research shows that taking biotin daily at doses of 100 to 300 mg may improve visual acuity and paraparesis (light paralysis of the lower limbs) in some patients with progressive multiple sclerosis. A dose of 300 mg per day appears more effective. Treatment may take up to 8 months before clinical improvement is observed. Moreover, biotin does not seem to prevent disease relapse.
Posologie
Oral
100 - 300 mg
8 - months
Adults
Hair Loss ✪✪✪✪✪
Some clinical evidence has shown that biotin supports hair regrowth in children with alopecia areata, an abrupt and non-scarring hair loss in circumscribed areas affecting genetically susceptible individuals exposed to poorly defined environmental triggers. A dose of 20 mg per day of biotin has been used orally in combination with zinc aspartate at 100 mg/day and topical clobetasol propionate at 0.025% for one year in 9-year-old children.
Posologie
Oral
20 mg
1 - years
Children
Synergies
Brittle Nails ✪✪✪✪✪
Clinical evidence shows that taking 2.5 mg of biotin daily, orally, for 1.5 to 15 months, increases nail thickness by 25% and reduces nail splitting in women with brittle nails or onychoschizia (nail splitting and detachment).
Posologie
Oral
2.5 mg
15 - months
Women
Properties
Essential
Biotin is an essential vitamin, found in foods bound to proteins and cleaved by the enzyme biotinidase. Biotin is stored in the mitochondria and acts as a coenzyme in bicarbonate-dependent carboxylation reactions. Biotin-containing enzymes are involved in gluconeogenesis, fatty acid synthesis, propionate metabolism, and leucine catabolism in mammals. Moreover, pyruvate carboxylase, a key enzyme of gluconeogenesis, is a biotin-dependent enzyme. A decrease in the activity of this enzyme during a biotin deficiency can lead to the accumulation of pyruvate or a decrease in aspartate concentration. European health authorities (EFSA, European Food Safety Authority and the European Commission) estimate that products containing vitamin B8 can claim to contribute to normal energy metabolism, normal functioning of the nervous system, maintenance of hair, normal skin and mucous membranes, normal food metabolism and normal mental functions.
Usages associés
Hypoglycemic
In both diabetic and non-diabetic subjects, blood glucose levels decrease when plasma and tissue concentrations of biotin increase. This effect is more significant in diabetic subjects. Animal research suggests that biotin reduces blood glucose levels by stimulating the expression of hypoglycemic enzymes such as insulin, pancreatic glucokinase, and hepatic glucokinase, and inhibiting the expression of hepatic phosphoenolpyruvate carboxykinase (an enzyme that stimulates glucose production).
Usages associés
Hypolipidemic
In animals, some evidence suggests that biotin may affect lipid metabolism by decreasing the activity of acetyl-CoA carboxylase 2 (ACC 2), an enzyme that regulates fatty acid oxidation. Decreased ACC 2 activity appears to increase fatty acid oxidation by reducing malonyl-CoA levels.
Fertility Effect
Biotin deficiency seems to be associated with impaired spermatogenesis and decreased sperm count. In animals, biotin deficiency is associated with decreased testicular and serum testosterone levels. Treatment with biotin in conjunction with testosterone seems to normalize spermatogenesis in these animals.
Neurological
High doses of biotin seem to improve symptoms of multiple sclerosis by activating the Krebs cycle in demyelinated nerve cells and activating fatty acid synthesis necessary for myelin synthesis.
Usages associés
Safety dosage
Infants up to 12 months: 6 µg
Children from 1 to 3 years: 20 µg
Children from 4 to 10 years: 25 µg
Children from 11 to 17 years: 35 µg
Adults from 18 years: 40 µg
Breastfeeding women from 18 years: 45 µg
Pregnant women from 18 years: 40 µg
Interactions
Médicaments
Cytochrome P450 substrates: moderate interaction
In vitro, biotin supplementation induces the activity of cytochrome P450 1B1 (CYP1B1). Theoretically, biotin may decrease the levels of drugs metabolized by this enzyme.
