(b) Taking all necessary measures to ensure the right of the child to the enjoyment of the highest attainable standard of health and developing sustainable health systems and social services, ensuring access to such systems and services without discrimination, paying particular attention to adequate food and nutrition and assigning priority to activities and programmes aimed at preventing addictions, in particular addiction to alcohol and tobacco, and the abuse of narcotic drugs, psychotropic substances and inhalants and by, inter alia, securing appropriate prenatal and post-natal care for mothers;