Vitamin A deficiency harms stem cells, study says

Scientists have identified a vitamin A metabolite known as retinoic acid that is vital to the process of activating and inactivating stem cells to regenerate cells.

By Amy Wallace

May 5 (UPI) -- Researchers at the German Cancer Research Center have found deficiencies in vitamin A can be detrimental to blood stem cells.

Specialized cells in the skin, gut or blood have a relatively short lifespan and require steady replenishment. They come from adult stem cells dividing continuously to survive.


In 2008, researchers discovered a group of special stem cells in the bone marrow that remain dormant most of the time and only become active to fight bacterial or viral infections, heavy blood loss or as a reaction to chemotherapy. When their work is done, the body sends its most potent stem cells back into dormancy.

Researchers have now identified the mechanisms that activate and deactivate the stem cells. They found retinoic acid, a vitamin A metabolite crucial to the process. When retinoic acid is absent, active stem cells are unable to return to a dormant state and mature into specialized blood cells instead.

In studies with specially bred mice, researchers found the stem cells are lost as a reservoir if they lack retinoic acid.

"If we feed these mice on a vitamin A deficient diet for some time, this leads to a loss of stem cells," Nina Cabezas-Wallscheid, lead author of the study, said in a press release. "Thus, we can prove for the first time that vitamin A has a direct impact on blood stem cells."


The study sheds new light on previous studies that show vitamin A deficiency impairs the immune system.

"This shows how vitally important it is to have a sufficient intake of vitamin A from a balanced diet," Cabezas-Wallscheid said.

Researchers hope the findings may play a role in cancer treatments because cancer cells, like stem cells, rest in a state of dormancy and their metabolism is completely shut down, making them resistant to chemotherapy.

The study was published in Cell.

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