RDA: Not yet developed. 100-200 mcg/day is considered adequate and safe.

Roles of biotin in the body

• A coenzyme required for fatty acid synthesis
• Also helps metabolize amino acids and carbohydrate
• Helps maintain healthy skin, hair and a balanced hormonal system

Deficiency: Biotin deficiency is rare but can develop from excessive daily intake of over 12 raw egg whites (which contains a protein, avidin, that binds biotin and prevents its absorption; avidin is destroyed by cooking).

Symptoms include dermatitis, glossitis, lethargy, muscle pains, nausea.

Good food sources of biotin: Intestinal bacteria provide most of our biotin requirements, but biotin is also present in a variety of foods. Best sources include egg yolks, liver, yeast, nuts, milk, fresh vegetables.