According to senior author Dr. Lorraine Gudas – chairman of the Department of Pharmacology at Weill Cornell – and colleagues, vitamin A boosts beta cell activity, meaning lack of the vitamin may play a role in the development of type 2 diabetes.
There are two types of vitamin A. Preformed vitamin A, referred to as retinol, is present in meat, poultry, fish and dairy products, while pro-vitamin A, or beta-carotene, is found in many fruits and vegetables. Vitamin A aids cell growth and contributes to a healthy immune system and vision.
Past studies have shown that, during fetal development, vitamin A is key for beta cell production. But Dr. Gudas and colleagues say it was unclear as to whether vitamin A played such a role in adulthood.
To find out, the team analyzed the beta cell development among two groups of adult mice; one group of mice had been genetically modified to be unable to store dietary vitamin A, while the other group was able to store the vitamin from foods as normal.
The researchers found that the mice unable to store vitamin A experienced beta cell death, meaning these mice were unable to produce insulin.
What is more, when the researchers removed vitamin A from the diets of healthy mice, they found this led to significant beta cell loss, resulting in reduced insulin production and increased blood glucose levels – key factors involved in development of type 2 diabetes. When the researchers restored vitamin A to the rodents’ diets, beta cell production rose, insulin production increased and blood glucose levels returned to normal.