If your tiny tot avoids fruit and veggies, he or she could be courting curtailed mental abilities. Shocking, but that is the implication of a just-published study in the American Journal of Clinical Nutrition. Danish researchers observed that young guinea pigs on a low-vitamin C diet exhibited the human equivalent of learning defects — taking up to six times longer to swim through a water maze. Data showed the difference was indeed vitamin C’s effects on the brain: The nutrient-deficient subjects had 30% fewer neurons responsible for memory and spatial direction.

“We may be witnessing that children get learning disabilities because they have not gotten enough vitamin C in early life,” said study author Professor Jens Lykkesfeldt. The good news is that even finicky eaters can eat to meet their vitamin C requirements. Though the chart below shows how much a half cup of top sources provide, even a quarter cup puts toddlers over 100%.

Source (1/2 cup)
 DRI Ages 1-3
 Kiwifruit  556%
 Red Bell Pepper  391%
 Broccoli, cooked  337%
 Strawberries  282%
 Pineapple  262%
 Brussels Sprouts  249%

In addition to brain benefits, adequate vitamin C helps growing bodies absorb more iron from other sources, build strong bones and fend off infection. Vitamin C is key not just for kids, but also for pregnant moms, to help ensure proper fetal neurological development. Another crucial but less well-known nutrient needed during pregnancy to safeguard children’s later mental aptitude: choline, found in wheat germ, salmon and eggs.

Bonus: Increased consumption of omega-3 fatty acids from fish and nuts has been linked to higher test scores among children.

Published February 1, 2010