Given the low quality diet of many poor people, particularly the urban poor who live in "food deserts", nutritional supplements probably would be helpful. The information on those isn't really packaged for the low income consumer, or even the middle-income consumer who doesn't think about it.
Prenatal vitamins are almost certainly the low-hanging fruit, though, although with 10-30 year lag.
Prenatal vitamins are almost certainly the low-hanging fruit, though, although with 10-30 year lag.