sentences:  Comprehensive policy recommendations targeting reduction of cognitive impairment in children have been proposed.Improvements in nutrition (often involving specific micronutrients) due to public policy changes have been implicated in IQ increases in many nations (as part of the overall Flynn effect), such as efforts fighting iodine deficiency in the U.S.
  
  Malnutrition may occur during several periods of growth, such as pregnancy, during breastfeeding, infancy, or childhood.It may also happen due to deficiencies of different nutrients, such as micronutrients, protein or energy.