From past experience sharing this idea, I know that very few people will see the connection. But maybe persistence will pay off.

Namely, the brain needs good biochemistry to function. That's why antidepressants help the suicidal, and why Ritalin helps kids with ADD.

So what would Mother Nature suggest for closing the Gap? She'd point out that we've been tip toeing around the color issue yet that's a big clue. The more melanin in a person's skin, the longer it takes to make vitamin D. Therefore, if all kids get about the same D in their food but pale kids can make more D from sunlight, they will have better brain chemistry--- better memory, better self control, less asthma and infections and therefore fewer absences (which undermine achievement).

To compensate for making less from the sun, a child of color would benefit from D supplementation. There are very few foods which contain enough D to make a difference. Many foods are fortified, but D2 is used (it's less effective than D3) and the amount is still too low to make much difference.

Sardines can boost a student's D level because we eat almost the whole fish, and therefore we get the D-rich liver. Try sardines with lemon juice or salsa. Believe it or not, when I've offered sardines to my students, about 2/3 of the class ate them, and some kids asked for seconds and even thirds!

Salmon and tuna also have high levels of D, but tuna is very high in mercury and dioxin.

Read about D closing the Gap at:
http://goodschoolfood.org/pdf/D-Light-Full_VitaminD.pdf