A biotin deficiency can affect many different body systems. Biotin is an essential B-vitamin, used for enzyme functions, metabolic activities, and genetic processing.
The US Food and Nutrition Board (FNB) have set the recommended daily adequate intake for biotin at 30 micrograms for adults age 19 and older. During pregnancy, the need for biotin does not increase, but women are at a higher risk of developing a marginal (mild) deficiency. Breastfeeding women do require more biotin--about 35 micrograms a day.
Prevalence of Biotin Deficiency
Biotin deficiency is rare because the daily requirement is relatively small and biotin is found in many foods. Some studies have estimated the average daily intake of American adults to be between 40 and 60 micrograms, meeting the recommendation from the FNB. Some potential causes of biotin deficiency include long-term use of certain anti-seizure medications, prolonged antibiotic use, intestinal malabsorption, and excess intake of raw eggs.
Signs and Symptoms of Biotin Deficiency
The most common signs of a significant biotin deficiency include hair loss and a scaly red rash around the eyes, nose, and mouth. This characteristic facial rash has been termed “biotin deficient facies” and is typically accompanied by an unusual facial fat distribution. Other physical signs of biotin deficiency can include brittle nails, thinning eyebrows and eyelashes, and dermatitis or eczema in children.
Because biotin is necessary for energy production by synthesizing fatty acids and carbohydrates, a deficiency in the vitamin can lead to lethargy or fatigue. Some deficient people may also experience neurological symptoms, including numbness and tingling in the hands and feet, generalized muscular pain (myalgias), depression, and hallucinations.
Due to its role in the processing of fatty acids, a deficiency in biotin has also been linked to high levels of circulating lipids (high blood cholesterol). Biotin deficiency has also been linked to keratoconjunctivitis, and inflammation of the cornea and conjunctiva in the eye.
Anemia can occur as a result from a deficiency in biotin. Biotin is necessary for the synthesis and utilization of two important B-vitamins, folic acid and vitamin B12 that are needed for healthy red blood cells.
Some patients, particularly those with a hereditary disorder that leads to a biotin deficiency, may experience an impaired immune system function because of defects in T and B cells. This can lead to an increased susceptibility to both bacterial and fungal infections.
Biotin Deficiency in Pregnancy
Some research has found that biotin is broken down more rapidly during pregnancy, leaving women at a higher risk of developing a deficiency. This is a concern, because animal studies have found that even a mild deficiency in biotin can lead to teratogenesis, the abnormal development of the fetus, and birth defects.
Biotin is found in many foods, with the richest sources being egg yolks, liver, and nutritional yeast. Other good sources include cheddar cheese, whole grains, legumes, pork, salmon, avocado, raspberries, and cauliflower. Biotin is also synthesized by the bacteria in both the small and large intestine