Biotin is one of the B-complex vitamins important to energy metabolism, particularly that of fatty acids and protein. It also plays a critical role in blood sugar regulation and in the activity of certain enzymes. Biotin is readily available in many foods, and deficiency is uncommon.
Biotin Requirements for Healthy Adults
The U.S. Food and Nutrition Board, a part of the National Academy of Science’s Institute of Medicine, recommends that healthy adults achieve a daily adequate intake of 30 micrograms of biotin. For pregnancy and lactation, the minimum required is only slightly higher, at 30-35 micrograms. Most women achieve this easily in the diet. Senior adults are not known to need any more of the B-vitamin than younger adults.
Symptoms of Biotin Deficiency
The signs of a significant deficiency in biotin include alopecia (hair loss) and a scaly red rash around the eyes, nose, mouth and genital area. Neurologic symptoms may include depression, lethargy, and numbness or tingling in the hands or feet.
Factors that Affect Biotin Needs
For the most part, biotin deficiency is relatively rare, but certain factors can increase the body’s need for the vitamin, placing one at risk of a shortage if intake is low. Pregnancy and lactation, for example, increases the needs for many nutrients, including biotin. It is thought that pregnancy increases the catabolism, or breakdown, of the nutrient to provide energy for fetal growth.
Certain health conditions can put a person at risk for a biotin deficiency. Patients who have had part of their stomach removed for cancer or severe ulcers (called a partial gastrectomy) or those who have had their stomach bypassed (as in the case of a gastric bypass) have a greater need for biotin. Alcoholics have been found to have lower levels of circulating biotin than the general population. Those who suffer from epilepsy may also have a reduced level of biotin, likely due to the interaction between the vitamin and anti-seizure medications such as Dilantin.
Although biotin is crucial in blood sugar metabolism, those with diabetes are not proven to have an increased need over the guidelines listed above for the general healthy population. However, uncontrolled diabetes (high blood sugar levels) have been associated in at least one study on laboratory animals with low levels of serum (blood) biotin.
Other common medications may interfere with biotin absorption. Broad-spectrum antibiotics, sulfa drugs for example, can alter the amount of intestinal bacteria that provide a non-dietary source of biotin. Accutane, used to treat severe acne, may also reduce the activity of biotin. Patients on these medications should check with their physician to see if biotin supplementation is appropriate.
Food Sources of Biotin
The best food sources of biotin include yeast, whole-wheat bread, liver, chicken eggs, leafy greens such as Swiss chard and spinach, and in some fruits and vegetables such as avocado, raspberries and cauliflower. Cooking and preserving may slightly lower the biotin content of food, except in the case of eggs. A cooked egg has more available biotin than a raw egg because of a protein called avidin, which binds the vitamin when raw, but releases it when cooked.