1. Which of the following is the recommended daily dietary intake of biotin?

• 10 mcg/day
• 20 mcg/day
• 30 mcg/day
• 40 mcg/day

2.  Which of the following could be the causes of biotin deficiency?

• Biotinidase deficiency
• Administration of broad-spectrum antibiotics
• Inflammatory bowel disease
• Any of the above

3. Which of the following drug administration can cause biotin deficiency?

• Carbamazepine
• Phenytoin
• Isotretinoin
• Any of the above

4. A 12 year old girl presents with alopecia and recurrent periorificial dermatitis. Which of the following diagnostic tests can be useful to diagnose biotin deficiency in this patient?

• Urinary 3-hydroxyisovaleric acid
• Propionyl-CoA carboxylase in lymphocytes
• Urinary biotin
• All of the above

5. State whether the following statement is true or false:

Consumption of large amounts of raw egg whites can lead to acquired biotin deficiency.

• True
• False