Vitamin E is a fat-soluble vitamin with antioxidant properties. Natural vitamin E exists in eight different forms: alpha, beta, gamma, and delta tocopherol; and alpha, beta, gamma, and delta tocotrienol. Alpha-tocopherol is the most active form in humans. In foods, vitamin E exists primarily as mixed tocopherols. Foods that contain vitamin E include: eggs, fortified cereals, fruit, green leafy vegetables, meat, nuts/nut oils, poultry, vegetable oils and whole grains. Vitamin E supplements are available in natural or synthetic forms. While the precise rate of vitamin E absorption is not known with certainty, it is believed to be variable and low. Reported rates of absorption of vitamin E following intake with food have varied from as high as 51%-86% to as low as 21%-29% 1. All forms of vitamin E, including all of the tocopherol and tocotrienol homologues, are absorbed through the intestine in a similar manner.
The U.S. Food and Drug Administration (FDA) has established a Reference Daily Intake (RDI) of 30 international units (IUs) vitamin E for adults and children 4 or more years of age (21CFR101.9). RDIs are a set of dietary references for essential vitamins and minerals that are considered amounts sufficient to meet the daily requirements of healthy individuals. RDIs serve as the basis for calculating the percent daily value (%DV) amounts found on dietary supplement and food labels.
Rice bran is made from the bran layer, underneath the hull layer, of rice, Oryza sativa. Rice bran is high in dietary fiber, and is an excellent source of protein, vitamin E, thiamin, niacin, vitamin B6, pantothenic acid and a number of minerals, such as iron and magnesium. It is also a good source of folate and riboflavin 2. Rice bran also contains beta-sitosterol and other phytosterols, along with the essential omega-3 fatty acid alpha-linolenic acid (ALA) 3.
Rice fiber is the soluble and insoluble fiber obtained from the bran layer of the rice kernel.