Biotin Deficiency

Biotin deficiency

Biotin is a member of the B-complex vitamins essential to maintain body function. It converts carbohydrates into energy and also aids in fat and protein metabolism. ^[1] When there is lack of biotin, a nutritional disorder called biotin deficiency results.

Animal organ meats like liver and kidney are said to be the best source of biotin. ^[1] Other good sources are egg yolk, milk, soya, barley and Brewer's yeast. ^[2] The recommended dietary allowance (RDA) for biotin by the U.S. is only 300 micrograms/day making true biotin deficiency uncommon. ^[3]             

Causes

Egg whites have been found out to contain proteins which inhibit biotin absorption therefore consumption of large amounts of egg whites can lead to biotin deficiency. ^[4]

People at risk for developing biotin deficiency are patients taking anticonvulsant drugs and those on prolonged antibiotics. ^[3] The condition can also arise from genetic mutations in the biotinidase gene (BTD). Patients on total parenteral nutrition can also develop biotin deficiency hence it is recommended that biotin supplementation be given. ^[5

Signs and Symptoms

Early manifestations are related to skin and hair. Dry skin with seborrheic dermatitis is a typical finding. ^[6] Skin lesions may precipitate fungal infections. Periorofacial rash is a common finding and the hair may become fine and brittle often resulting to hair loss.

About 55% of pediatric patients with biotinidase deficiency have sensorineural hearing loss. The nervous system is affected with the symptoms nonspecific and varying from person to person. Symptoms may include depression, seizures, muscular pains, numbness or tingling sensations and increased sensitivity to sensory stimuli. Nausea and anorexia may also be present. ^[5]

Diagnosis

The history of patient is obtained especially his or her diet. Diagnosis is primarily based on clinical findings. Some laboratory parameters that may aid in diagnosis include levels of serum ammonia, urine ketone, quantitative plasma amino acid and plasma carnitine. In cases where there are confusing manifestations, MRI and biopsy may be indicated. Profound deficiency of biotinidase can be identified with newborn screening. ^[5]

Treatment

Patient is given adequate amounts of biotin and is advised to consume well-balanced diet with adequate calories. Treatment also depends on the cause of biotin deficiency. For instance, if anticonvulsant therapy is the underlying cause, the drug is changed to another or a biotin supplement is given. ^[5]

References:

1. http://www.livestrong.com/article/508268-what-are-the-causes-of-biotin-deficiency/

2. http://www.rightdiagnosis.com/b/biotin_deficiency/intro.htm

3. http://arathi-srikantaiah.suite101.com/what-are-the-causes-of-a-biotin-deficiency-a268902

4. http://www.livestrong.com/article/508268-what-are-the-causes-of-biotin-deficiency/

5. http://emedicine.medscape.com/article/984803-clinical#a0218

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