Vol. 7, No. 1, 2001 Page 4

Vitamin A deficiency linked to learning problems

Criminal behavior is strongly linked to learning disabilities, and a new study indicates that some learning disabilities, in turn, are linked to vitamin A deficiency. The good news: the problem is not just preventable, but also reversible.

Ronald Evans et al. at the Salk Institute found that vitamin A-deficient diets diminished two chemical changes associated with learning, long term potentiation (LTP) and long-term depression (LTD), in the mouse hippocampus. "At 15 weeks of age, the responses of vitamin A-deprived mice are reduced to about 50 percent normal," Evans et al. say. "At longer time points, LTP is stable at 50 percent, but LTD drops to almost undetectable levels."

Remarkably, these changes were reversed within two days when the mice received vitamin A in their diets. The researchers also showed that LTP and LTD activity normalized when the mice's hippocampal cells were bathed in vitamin A. This indicates, the researchers say, that the vitamin directly affects this brain area, which plays a primary role in memory and learning.

Evans et al. say, "The study indicates that the detrimental effects of vitamin A deprivation are remarkably reversible, which offers hope to the millions of children worldwide with vitamin A-deficient diets."

In earlier research, Evans et al. showed that mice bred to lack genes for two vitamin A receptors performed poorly on tests of memory and spatial ability. They speculate that "vitamin A is a type of molecular key that unlocks one of the most powerful functions of the human brain."

Nearly 190 million children worldwide suffer from vitamin A deficiency. While outright deficiencies of vitamin A are rare in the U.S., studies show that inner-city children have low levels of this nutrient. Survey data also indicate that nearly half of adult men and women consume less than half the recommended amount of vitamin A.


"Vitamin A lack impairs learning, but it's reversible," UniSci Daily University Science News, November 8, 2000.

Return to:
[Author Directory] [Front Page] [Issue Index] [Subject Index] [Title Index]