Vitamin A Deficiency and Cognition

"We have known for some time there is less vitamin A in the blood of people with Alzheimer's compared with people who have normal cognitive function. What we didn't know was how important it could be in early childhood development."
"Vitamin deficiency during pregnancy is much more harmful [to the fetus] than a vitamin deficiency later in life."
"If you give vitamin A supplements in the first month or two of life, you can reprogram the brain and restore most of the cognitive function. If you wait two months, the supplements don't work as well."
"The World Health Organization report says there are 250 million preschoolers in the world with vitamin A deficiency. In developing countries, vitamin A deficiency is quite common and likely affects many pregnant women."
Weihong Song, Canada Research Chair, Alzheimer's disease, University of British Columbia

New research shows that mice deprived of vitamin A in the womb may have higher levels of beta amyloid (here shown as plaque in the brain of an Alzheimer's patient). Medical News Today

In 2015, international researchers discovered a link between vitamin D deficiency and the onset and development of Alzheimer's and dementia, by studying and observing over one thousand, six hundred seniors for a period of six years. It is estimated that between 40 and 75 percent of all adults are deficient in vitamin D, representing a group of secosteroids responsible for the absorption of calcium, iron, magnesium, phosphate and zinc. Essentially vitamin D has a hormonal action.

Only a few foods confer the benefits of vitamin D, though the human body absorbs it through exposure to sunlight. Most people require the use of vitamin D supplements to boost the body's critical store.

Now, researchers at the University of British Columbia in Vancouver have published a study appearing in the journal Acta Neuropathologica, pointing out that vitamin A deficiency may trigger Alzheimer's disease late in life. Even mild vitamin A deficiency in animal models had the effect of increasing production of amyloid beta, protein fragments which form plaques in the brain. People with Alzheimer's suffer from amyloid plaques which smother and in time kill neurons as dementia steadily advances.

A new study has found that mice deprived of vitamin A before birth are more likely to develop symptoms of Alzheimer's disease. (Robert F. Bukaty/The Associated Press)

Gene mutations and environmental factors over a prolonged period of time cause Alzheimer's disease. Mice engineered with a mutated human gene to render them susceptible to Alzheimer's were used in this laboratory study which discovered that fetal malnutrition leads to learning problems that will last a lifetime. Deprived of vitamin A through their mother's diet, fetal mice performed poorly on tests of learning and memory when they reached adulthood.

And this was so irrespective of their being exposed to a normal diet directly post-birth.

Dr. Song and his research collaborators at the Children's Hospital of Chongqung Medical University in China "rescued" brain function in mice with vitamin A supplements applied directly after birth.

Brain health in the developing world and in remote parts of China and elsewhere in the world where food choices are limited, point out why those not obtaining sufficient vitamin A in the diet severely compromises cognitive health. Vitamin A can be found in fish and in brightly coloured fruits and vegetables, all of which may be in short supply in deprived areas where lack of essential foods and fruits deprive people of vitamin A.

"We have known for some time there is less vitamin A in the blood of people with Alzheimer's compared with people who have normal cognitive function," said researcher Weihong Song. "What we didn't know was how important it could be in early childhood development." Martin Dee / Vancouver Sun