Vitamin A deficiency is a widespread problem in developing countries and there are efforts to give children, particularly neonates (children younger than 1 month of age), vitamin A supplements. To gain a better understanding of neonatal vitamin A supplementation, researchers examined the way vitamin A is processed and the areas to which it travels throughout the bodies of neonatal rats.
Vitamins are vital nutrients that we obtain through our diets to keep our bodies healthy and functional. There are many types of vitamins and one very important one is vitamin A. The lack of vitamin A can lead to night blindness and is also related to early childhood deaths. Vitamin A deficiency is often a result of childhood malnutrition, which is a large problem affecting many countries in Asia and Africa. As such, there have been many efforts worldwide to reduce vitamin A deficiency in children. One thing that scientists have noticed is that childhood mortality decreases when vitamin A supplementation is given to children younger than 1 month of age (neonatal, or newborn), but they do not see the same effect for children between 1 and 6 months of age. In a study published in the American Journal of Clinical Nutrition, the authors aim to explain this difference using an animal model. They examine how vitamin A is processed in different organs of the body and the differences among neonatal animals that allow them to benefit the most from vitamin A supplementation.
The authors of this study used neonatal rats deprived of vitamin A to model vitamin A deficiency in human newborns. Vitamin A gets processed into retinol, which is then used by our bodies. First, the authors fed neonatal rats vitamin A or no supplements and traced retinol in neonatal rats to see that it primarily goes to the liver. Rats that were supplemented with vitamin A also had significantly higher levels of retinol in the liver. Computer models were used to determine the ways by which retinol is taken up and processed by the animals. By supplementing neonatal rats with vitamin A, the authors determined that retinol is preferentially taken up by liver instead of more external organs, such as the skin. The retinol from the liver is then processed and released to be taken up from the blood supplied to various organs approximately 2 weeks later. This occurs to a greater extent when compared to rats that did not receive supplementation.
The experiments from this study look at how retinol, a processed form of vitamin A, is transferred through different organs and processed in different ways that allow for better uptake in neonatal rats. It is impossible to observe retinol levels in all the different organs in humans and therefore this model allows us to have a better understanding of the effectiveness of vitamin A supplements in neonates. Information from this study can pave the way for improved vitamin A supplementation schedules and guidelines.
Written By: Branson Chen, BHSc