Vitamin B8 (or biotin) is a water-soluble vitamin also known as vitamin H.
Biotin is a coenzyme that helps break down carbohydrates, certain amino acids, and fatty acids. Biotin also aids in the synthesis of vitamins B9 and B12.
What does vitamin B8 do?
Vitamin B8 doses are expressed in terms of adequate intake (AI) amounts, because data does not permit calculation of a recommended dietary allowance. There is generally little documentation regarding the amount of nutritionally available biotin: it is found in varying concentrations in a wide range of foods. Biotin is also produced naturally in the intestine by bacteria.
Patients undergoing hemodialysis and peritoneal dialysis treatments (procedures that mechanically remove waste the kidneys are not able to excrete normally), and persons deficient in biotinidase are likely to require more biotin.
Lacking sufficient data to determine a tolerable upper intake level (TUIL), individuals who consume nutrients in quantities that exceed the recommended adequate intake (AI) should exercise extreme care.
Recommended Adequate Intake* (AI) for Vitamin B8:
Source: DRI, Dietary Reference Intakes, The Essential Guide to Nutrient Requirements 2006, p.196.
*Lacking sufficient scientific evidence, authorities have established adequate intake (AI) amounts rather than recommended dietary allowances (RDAs). Adequate intake is based on observed average intakes in North Americans in good health.
Biotin is widely found in a variety of foods, but often in small amounts. The typical U.S. diet is estimated to provide approximately 40 µg of it per day. Royal jelly and brewers’ yeast are the only two foods that contain substantial quantities of biotin. The best natural human-grade food sources of biotin are liver, legumes, soy, Swiss chard, tomatoes, Romaine lettuce, and carrots. It is also found in almonds, eggs, onions, cabbage, cucumbers, cauliflower, goat milk, cow milk, raspberries, strawberries, halibut, oatmeal, and nuts.
Food Sources for Vitamin B8:
Biotin deficiency is relatively rare and harmless, and may be treated with supplements. This deficiency may be caused by excess consumption of raw egg whites (because of their elevated levels of avidin protein). Avidin binds tightly with biotin, thereby diminishing its absorption. Cooking alters avidin without affecting biotin.
In children, genetically based metabolic anomalies may be behind biotin deficiency. This deficiency appears as changes in immune system function and in a heightened susceptibility to bacterial and fungal infections.
Signs of vitamin B8 deficiency:
No harmful effects have been tied to excessive biotin intake.
Signs of excess vitamin B8:
Natural health products or vitamin supplements:
Drugs that may result in a vitamin B8 deficiency:
Speak with your pharmacist if you plan to take vitamin B8 supplements. Your pharmacist can help you choose the solution that’s best for you based on your health and any drugs you take.
Vitamin B8, Biotin, vitamin H