Biotin Content of Foods in Japan

Abstract

Biotin is widely contained in various foods. However, the content of biotin in foods is not on the 5th Revised Japanese Standard Food Table published in 2000. Also, the extent to which biotin is lost by food processing and cooking and the digestion and absorption of biotin in the gastrointestine remain unelucidated. Therefore, we determined the biotin contents of typical foods in Japan, and compared them with those in various foods available in other countries. The average content of biotin in pulses, nuts and seeds, eggs, seasonings and spices was more than 10μg/100g on average, but there was only a small amount in vegetables, fruits, milk, and fats and oils. The biotin content of Japanese seasonings differed considerably from that in seasonings from other countries. This is partially because rich sources of biotin are soy sause and fermented soybean paste in Japan, and yeast in other countries. These foods contained a high content of biotin. However, overall, there was no large difference in the biotin contents of foods among Japan, Germany and Denmark. The daily intake of biotin was calculated using the National Nutrition Survey in Japan, 2001, and the average content of biotin in the food groups investigated in this study. Biotin intake was 110μg/day for men and 92.3μg/day for women, being 244 and 206% of the Adequate Intake stated in Dietary Reference Intakes (2005 edition)., respectively. There were large difference in the biotin contents and the proportions of free biotin in foods. Egg yolk contained a large amount of free biotin, suggesting that this is a good source of biotin.