Vitamin A deficiency is the world’s leading cause of childhood blindness, and in severe cases it can be fatal. About a third of the world’s population of preschoolers suffer from this vitamin deficiency, which is most prevalent in sub-Saharan Africa and South Asia.
MIT researchers have now developed a new way to fortify foods with vitamin A, which they hope could help improve the health of millions of people around the world. In a new study, they showed that encapsulating vitamin A in a protective polymer prevents the nutrient from being broken down during cooking or storage.
“Vitamin A is a very important micronutrient, but it’s an unstable molecule,” says Ana Jaklenec, a researcher at MIT’s Koch Institute for Integrative Cancer Research. “We wanted to see if our encapsulated vitamin A could fortify a food vehicle like stock cubes or flour, throughout storage and cooking, and if the vitamin A could remain biologically active and be absorbed.”
In a small clinical trial, researchers showed that when people ate bread fortified with encapsulated vitamin A, the bioavailability of the nutrient was similar to that when they consumed vitamin A alone. The technology has been licensed to two companies who hope to develop it for use in food products.
“This is a study that our team is really excited about because it shows that everything we’ve done in test tubes and animals works safely and effectively in humans,” says Robert Langer, a professor at the David H. Koch Institute at MIT and Fellow of the Koch Institute. “We hope this will open the door to one day helping millions, if not billions, of people in the developing world.”
Jaklenec and Langer are the lead authors of the new study, which appears this week in the Proceedings of the National Academy of Sciences. The lead author of the paper is former MIT postdoctoral fellow Wen Tang, who is now an associate professor at South China University of Technology.
Vitamin A is essential not only for vision, but also for the functioning of the immune system and organs such as the heart and lungs. Efforts to add vitamin A to bread or other foods such as bouillon cubes, which are commonly eaten in West African countries, have been largely unsuccessful because the vitamin breaks down during storage or cooking.
In a 2019 study, the MIT team showed they could use a polymer called BMC to encapsulate nutrients, including iron, vitamin A and several others. They showed that this protective coating improved the shelf life of nutrients and that people who ate bread fortified with encapsulated iron were able to absorb the iron.
BMC is classified by the FDA as “generally considered safe” and is already used in drug and dietary supplement coatings. In the new study, the researchers focused on using this polymer to encapsulate vitamin A, a nutrient that is highly sensitive to temperature and ultraviolet light.
Using an industrial process known as the spinning disc process, the researchers mixed vitamin A with the polymer to form particles 100 to 200 microns in diameter. They also coated the starch particles, which prevents them from sticking together.
The researchers found that the vitamin A encapsulated in the polymer particles was more resistant to degradation by intense light, high temperatures or boiling water. Under these conditions, much more vitamin A remained active than when vitamin A was free or when it was delivered in a form called VitA 250, which is currently the most stable form of vitamin A used for food fortification.
The researchers also showed that the encapsulated particles could be easily incorporated into flour or stock cubes. To test their ability to survive long-term storage, the researchers exposed the cubes to harsh conditions, as recommended by the World Health Organization: 40 degrees Celsius (104 degrees Fahrenheit) and 75 percent humidity. Under these conditions, encapsulated vitamin A was much more stable than other forms of vitamin A.
“The increased vitamin A stability provided by our technology can ensure that foods fortified with vitamin A provide the recommended daily intake of vitamin A, even after long-term storage in a warm, humid environment, and cooking processes such as boiling or baking,” says Tang. “People who are vitamin A deficient and want to get vitamin A through fortified foods will benefit, without changing their habits. daily and without wondering how much vitamin A is left in the food.”
Absorption of vitamins
When the researchers cooked their encapsulated particles and then fed them to the animals, they found that 30% of the vitamin A was absorbed, as uncooked free vitamin A, compared to about 3% of the free vitamin A that had been cooked.
In collaboration with Biofortis, a company that performs food clinical trials, the researchers then assessed the quality of vitamin A absorption in people who ate foods fortified with the particles. For this study, researchers incorporated the particles into bread and then measured vitamin A levels in the blood over a 24-hour period after eating the bread. They found that when vitamin A was encapsulated in the BMC polymer, it was absorbed from food at levels comparable to free vitamin A, indicating that it is readily released in a bioactive form.
Two companies have licensed the technology and are focused on developing products fortified with vitamin A and other nutrients. A for-profit company called Particles for Humanity, funded by the Bill and Melinda Gates Foundation, is working with partners in Africa to integrate this technology into existing fortification efforts. Another company called VitaKey, founded by Jaklenec, Langer and others, is working on using this approach to add nutrients to a variety of foods and beverages.
The research was funded by the Bill and Melinda Gates Foundation. Other authors of the article include Jia Zhuang, Aaron Anselmo, Xian Xu, Aranda Duan, Ruojie Zhang, James Sugarman, Yingying Zeng, Evan Rosenberg, Tyler Graf, Kevin McHugh, Stephany Tzeng, Adam Behrens, Lisa Freed, Lihong Jing, Surangi Jayawardena, Shelley Weinstock, Xiao Le, Christopher Sears, James Oxley, John Daristotle, and Joe Collins.
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