A study conducted by the University of Aberdeen in Scotland suggests that it is the hypothalamus that controls the vitamin A levels in the body.
Previous studies concluded that the levels were regulated by other organs, such as the kidney and liver. The new research finds that that there may be top-down control of vitamin A function around the body.
This study, initially conducted on rats, identified a role for the brain in vitamin regulation and could have implications for diagnosis and treatment of vitamin-related diseases, from anaemia to infertility to blindness.
Vitamin A (widely used in the beauty world in the form or retinol), which cannot be self-produced by the body, is stored in the liver and, when the body is lacking the vitamin, can lead to weakening of the immune system as well as visual and skin problems.
Although it’s less common, an excess of vitamin A can be equally as impactful and can also lead to problems with both vision and the skin, as well as potential swelling of the brain.
Professor Peter McCaffery and Dr Peter Ikhianosimhe Imoesi, whose research was funded by the University of Aberdeen Elphinstone scholarship, conducted the study, which was also partially funded by the Biotechnology and Biological Sciences Research Council (BBSRC).
The study showed that application of very small amounts of vitamin A directly to the hypothalamus of the rat brain impacted the amount of vitamin A in the storage area of the liver and the amount of the vitamin distributed to cells of the body via the blood.
This observation suggests that a vitamin A sensor system is present in the hypothalamus, controlling how it is distributed through the body. The study also showed that the type of cells in the rat hypothalamus that may act to sense vitamin A are also present in the human hypothalamus.
Speaking on the findings, Dr Imoesi explained: “What we found is radically new. No one before has even suggested that the brain may control vitamin balance in the body, and this is the first study to imply a ‘vitaminostatic’ role of the hypothalamus.
“Our results suggest that vitamin A imbalance may not be simply due to irregular intake but that an abnormality in hypothalamic function due to disease or inflammation, may lead to inadequate supply of vitamin A to the body.
“Diseases that affect the hypothalamus may have some of their symptoms due to disordered vitamin A levels in the body. Measurement of vitamin A levels in the blood may provide a guide to whether the hypothalamus is functioning normally.”