Can the roots of Alzheimer's disease be programmed into the brain of a fetus or infant due to a lack of vitamin A? Yes, say researchers at the University of British Columbia who believe that biochemical reactions that eventually cause Alzheimer's disease begin in the womb or just after birth if the fetus or newborn doesn't get adequate vitamin A.

Their study, which was based on studies of genetically engineered mice, also found that supplements given to newborns with low levels of vitamin A could slow the disease.

According to the Alzheimer's Association, 5.4 million Americans are living with the disease, and the number may triple by 2050. Currently, Alzheimer's is the sixth leading cause of death in the United States.

"Our study clearly shows that marginal deficiency of vitamin A, even as early as in pregnancy, has a detrimental effect on brain development and has a long-lasting effect that may facilitate Alzheimer's disease in later life," said Dr. Weihong Song, a professor of psychiatry and Canada Research Chair in Alzheimer's Disease.

Song's research built on previous studies that have linked low levels of vitamin A with cognitive impairments. For the study, Song and his colleagues examined the effects of vitamin A deprivation in the womb and infancy on mice programmed to develop Alzheimer's. These early developmental stages are crucial periods during which brain tissue is "programmed" for the rest of a person's life.

The researchers found that even a mild vitamin A deficiency increased the production of amyloid beta, the protein that forms plaques that kill neurons in Alzheimer's disease. Song also found that these mice, when deprived of vitamin A, performed worse as adults on a standard test of learning and memory.

Even when the mice deprived of vitamin A in the womb were given a normal diet as pups, they performed worse than mice who received a normal amount of the nutrient in the womb but were deprived after birth. In other words, the damage had already been done in the womb.

"In some cases, providing supplements to the newborn Alzheimer's disease model mice could reduce the amyloid beta level and improve learning and memory deficits," said Song. "It's a matter of the earlier, the better."

A balanced diet is the best way to ensure adequate levels of the nutrient. Vitamin A is found in many foods, including carrots, sweet potatoes, eggs, and spinach. It helps keep vision sharp (mom was right — eat your carrots), boosts immune function, and is important in reproduction.

High doses can be toxic, so pregnant women should not take excessive vitamin A supplements, and should consult with their doctor for guidance. The RDA for vitamin A is 1,000 IU for children 1-3 years and rises to 3,000 IU for adults.